Rosalie is the widow of Jackie Aprile, Sr, and the mother of Jackie, Jr. and Kelli. She is good friends with mob wives Carmela Soprano and Gabriella Dante, to whom she offers characteristically frank advice.
Rosalie was always frank with her friends that she knew her husband, Jackie, had affairs, but seemed to have made her peace with his infidelity. During her marriage to Jackie, Ro had an affair with a man named Steve from her gym, which remained a source of guilt.
One year after Jackie Sr.'s death, she started a relationship with Ralph Cifaretto. Ralph had been a friend of Jackie's growing up and later a soldier in Jackie's crew before he moved to Miami. Their relationship became romantic after Ralph returned from Miami in 2000, following the deaths of both Jackie Sr. and Rosalie's brother-in-law, Richie Aprile. Ralph encouraged Jackie Jr. as he became more and more involved in the family business, providing him with a gun, accepting payments from him, involving him in making collections, and offering advice. Jackie Jr. tried to make a name for himself by robbing a card game (inspired by Ralph's telling the story of how Jackie Sr. made a name for himself by robbing a card game with Tony Soprano), but the heist went awry and a contract was put out on him. Unbeknown-st to Rosalie, it was Ralph who ordered her son's death. Jackie Jr.'s cousin, Vito Spatafore, executed the hit, and the official story (as told to Rosalie, the rest of her family, and family friends) was that Jackie Jr. was killed by black drug dealers.
Following her son's death, Rosalie sunk into a prolonged period of mourning. Ralph began an affair with Janice Soprano. Rosalie's friend Karen Baccalieri died soon after Jackie Jr., and Ro's depression worsened. Ralph chose this opportunity to break up with Rosalie, claiming he was tired of her constant grief. Rosalie, angered by his selfishness, ordered him out of her home. (He left and attempted to move in with Janice.) She eventually forgave him, though, and visited him when his son was in the hospital.
Rosalie has always been a loyal friend to Carmela, and her advice to her friend is generally loving but blunt. Of particular note was their discussion of A.J. after he dropped out of college in season six. Rosalie told Carmela to be firm with A.J., because she didn't want Carmela to make the same mistakes she had, and end up burying her son. Rosalie also advised Carmela throughout the latter's flirtation with decorator Vic Musto — warning her of the dangers of infidelity and the guilt from her own experience but was supportive about the difficulties of living with the double standards inherent in a mafia marriage. Rosalie is considered an aunt by Carmela's children.
Rosalie had severed her relationship with Angie Bonpensiero following Big Pussy's disappearance (he was believed by the wives to have entered the witness protection program), but they ultimately reconciled and Angie discussed her increasing business involvement with the Soprano/DiMeo crime family with Rosalie. Rosalie belongs to the same church as Carmela and is a friend of Father Phil Intintola — she thinks of him as a sweet man. After Carmela pulls back from her relationship with Father Phil he seems to replace her with Rosalie. Rosalie was also friends with Adriana La Cerva (to whom she was related by marriage through Jackie Aprile) and attended her wedding shower.
Rosalie accompanied Carmela on a trip to Paris in the Season 6 episode "Cold Stones". They visited many of the city's sights and Ro lit candles for her late husband and son in a church. While there, she pursued a brief relationship with a much younger Frenchman named Michel. Carmela upset Rosalie by asking about her grief over her son and husband while they were supposed to be enjoying their trip, but Rosalie was quick to forgive her friend. She also comforted Carmela through some difficult moments while they were away. Rosalie attended Bobby's wake in the series finale, "Made in America".