The friends and family of the JAG characters play a significant role in understanding the series sub-plots. I haven't listed all of them because not all screen captures have been possible but I have tried to include those of significance. [I decided to include this category late in my gathering of JAG episode data - so they are less complete. More are added as I obtain them.
Harm's Family
Christina Pickles as Christina "Trish" (Rabb) Burnett
Harm's mother who waited a long time not knowing the disposition of her husband Harmon Rabb Sr. after he was shot down over Vietnam and listed MIA. She remarried Frank Burnett, an executive for Chrysler and lives in La Jolla California.
Jon Cypher as Frank Burnett
Harm's stepfather. He is a Vice President at the Chrysler Corporation and aided Harm financially in tracking down his father's location in Russia. Harm's obsession with his natural father apparently never let him get close to the boy but he told Harm that he was "the only son he'd ever had."
Jade Carter as Sergei Zhukov
The brother of Harm by his fathers Russian Wife. Sergei was not able to obtain US citizenship even with the DNA from Harm's fathers saliva off old letters kept by Harm's mother. Harm rescued him from a death sentence pronounced by an arms dealing general but couldn't keep him from getting "lonely" and going back to Russia when his US citizenship was denied.
Hallee Hirsh as Mattie Grace Johnson
Harms' ward. Owner of Grace Aviation where Harm got a job as a crop duster. Estranged from her alcoholic father Tom Johnson after her mother was killed in an automobile accident where he was driving. Harm petitioned for guardianship but she reconciled with her father and went back to him. She was injured while taking a flying lesson.
David James Eliot as Harmon Rabb Sr.
Harm's father - shot down & MIA in Vietnam. Taken to Russia, but escaped to the countryside & lived with peasant farmers until killed defending his "wife" after fathering Sergei. Richard Crenna performed his voice.
Leeza Vinnichenko as Pitchta
Harm's stepmother. She took Harmon Rabb Sr in when he escaped from KGB captivity. They had a son Sergei before Harmon was killed while protecting her from drunken Russian soldiers and buried in an unknown grave in the Tiga forest.
as Mrs. Rabb
(in "ghost ship")
Unshown as Paternal grandmother Sarah Rabb
Harm spent a few months with her in Belleville Pennsylvania learning about his father and grandfather and receiving their old Stearman plane which he refurbished and flies with pride.
Meg's Family
Steven Ford as Dan Austin
Megs father who appeared to her while she was in a coma from being shot by an assassin.
Mac's Family
Conchata Farrell as Deanne MacKenzie
Mac's mother. She was abused by Mac's alcoholic father and abandoned them on Mac's 15th birthday taking the family dog with her. Mac reconciled with her at the deathbed of her father saying she forgave her for abandoning her.
Un-credited as Joseph MacKenzie
Mac's abusive alcoholic father who raised her after her mother left. Estranged, he only followed her career in the newspaper clippings that he saved. He was in a coma at death when Mac finally made peace with him. Said through father Genaro that he was most proud of Mac for rising above his failure as a father.
Mae Whitman as Chloe Madison
Mac considers her an "adopted daughter" although technically she was assigned as a "little sister" needing a lot of guidance. Her father is in the navy, mother deceased and she now lives with her grandparents in the country. She has Mac's old drug sniffing dog.
Carmen Argenziano as Matthew O'Hara
Mac's militia member uncle who took her to Red Rock Mesa in the desert & kept her safe looking for dinosaur tracks while she was drying out from alcoholism. She and Harm had to locate him when he stole the declaration of independence and Harm defended him at his trial.
Joe Lando as Christopher Ragle
Mac's estranged husband who attempted to kill Farrell and forced Mac to kill him. Was in prison and tried to extort money from Mac to pay back a "loan shark" after he got out.
Chegwidden's Family
Barbara Carrera as Marcella Paretti
Admiral Chegwidden's first wife. The daughter of the town mayor, she married A.J. because he "looked good in dress white uniform and had a good heart." She left him because of the "trail of blood" he had as a SEAL. She took Francesca back to Italy with her and married Vittorio Paretti. It was only many years later that she told AJ she wished he had come after her.
Giuliana Santini as Francesca (Chegwidden) Paretti
Admiral Chegwidden's daughter who has been raised by her mother and Mafioso step father, Vittorio Pareti, in Italy. The admiral had to rescue her from kidnappers brought about by her step-fathers' stealing stolen goods from a rival "family."
Jon Pennell as Lt Sherkston
As a youth he was sort of a Delinquent. He stole Chegwidden's car then, when chegwidden offered to drop the charges if he would join the navy, he did and became a SEAL. His wife, Shelly, called Chegwidden when "sharkey" was refusing treatment for Leukemia after having seen his father die emaciated following his cancer treatments. The admiral used "tough love" to help him "not ring the bell" and accept treatment in "Shakedown".
Ashley Drane as Lisa Rossbach
Admiral Chegwidden's goddaughter. The daughter of Merrill Rossbach, captain of a destroyer, Lisa ran away from her aunt's house for "sanctuary" at C's. A spoiled brat, she was rude, self-centered, demanding and dishonest whenever C didn't give her what she wanted. Her mother had to take leave in the middle of deployment to resolve her issues.
Roberts' Family
Matthew Michael Josten as A.J. Roberts
First child of Harriet and Bud Roberts named after Admiral A.J. Chegwidden (Albert Jethro). Had "vision" of his dad coming home when he was injured in a land mine explosion. He was born at JAG headquarters on the floor of Admiral Chegwidden's office and delivered by the Admiral himself.
Un-credited as Baby Girl & Boy Roberts
Bud and Harriet Roberts' latest twin children. They had an open house to introduce the children to Buds work friends who haven't seen them due to Harriet's departure from JAG.
Jeff MacKay as Big Bud Roberts
Bud Roberts Sr. Very authoritarian father to Bud and Mikey who physically abused them during childhood. Has somewhat questionable ethics but does sometimes come through for his kids.
Michael Bellisario as Mikey Roberts
Mike Roberts, Bud Roberts brother. Joined the Navy and went to the academy initially to get away from his abusive father known as "Big Bud" Roberts. Was charged and acquitted of negligence when his gun shot too close to marines. He is the love interest of Cammie Cresswell.
John Bennett Perry as Rowland Simms
Father of Harriet Simms Roberts. Reasonable, unaffected guy despite wealth and marriage to Lydia who hit him when he said "I hope Bud knows what he's getting into!"
Debbie McLeod as Lydia Simms
Harriet Simms Roberts mother. A pretentious, affected, meddling, domineeringly rude woman who nearly destroyed Harriet's wedding and tried to get Harriet to dump Bud and pursue Harm. However, Harriet pretty much takes after her.
Un-credited/Un-shown as Baby Sara
Many episodes were devoted to issues about baby Sara. She was asphyxiated at birth due to a prolapsed chord; but, she was never shown except "in utero."
Un-credited as James Kirk Roberts
Named by Bud, ostensibly without Harriet making the "connection" with Star Trek.
Creswell's Family
Joe Regalbuto as Wallace Cresswell
Brother of General Cresswell. Disaffected marine from Vietnam who had to shoot and kill a pilot trapped under his helicopter before he burned to death during a "black op."
Mel Harris as Dora Cresswell
General Creswell's bubbly, vivacious, outgoing "people person" wife. Opposites attract!
Danneel Harris as Cameron "Cammie" Cresswell
Is strong willed, self-centered, forward and aggressive. She has entered the Military academy and resents her father's continual pressure. She is not above cheating to win (at least in paintball.)
SECNAV Nelson's Family
Tony Crane as Brian Nelson
Alienated son of SECNAV Nelson. He was a Lt aboard USS Ellyson under tyrannical Cmdr Wallace Burke who "intentionally provoked him into disobeying an order for the sole purpose of punishing him later to - knock him down a peg." Unresolved issues with his father prevented him from the apology demanded by Burke.
Sturgis Turners Family
Bill Cobbs as Chaplain Turner
Chegwidden remembers him from Vietnam. He's brought back onto active duty once a year to give a Christmas sermon for many years. Sturgis remembers him as a strict disciplinarian.
Jason Tiner's Family
Jamison Jones as Edward Proxy
A coward and a liar who slugged and kicked Gunny's friend Manny while his arms were being held. Caught up in his own issues of being gay he convinced a candidate for states attorney he was "gay bashed." Jason Tiner's half brother.
Gunny Victor Galindez's Family
Wanda Acuna as Maria Galindez
One of four sisters of Gunny Victor Galindez. She is a paralegal law clerk by day and a fishing guide at other times. She took AJ Chegwidden on a fishing trip when he ended up saving Gunny from redneck assassins.
Jennifer Coates' Family
David Wells as Reverend Conrad Coates
Only shown once but maligned many times in the series. A fairly bigoted, "pseudo"clergyman which seemed to have made Jennifer's early life miserable.