Former first lady Rosalynn Carter died Sunday at 96. The wife of President Jimmy Carter for 77 years, she is being remembered for her roles as an adviser to the president and as an advocate and humanitarian in the decades after the Carters left the White House. And as her legacy is being remembered, a unique, little-known relationship is also being remembered: Mrs. Carter’s decades-long advocacy for and friendship with Mary Prince, a Black woman who went being wrongfully convicted of murder to becoming a nanny for the Carters’ children and a lifelong friend to the former first lady.

Mary Prince first met Jimmy and Rosalynn Carter in 1970 when she interviewed for a job working for Jimmy Carter, who was then the governor of Georgia. As noted in a 1977 profile in People magazine, Prince had earlier that year been convicted and sentenced for murder. The killing for which Prince went to prison happened outside of a bar where Prince had gone with a female cousin. The cousin got into an argument with another woman, which turned into a struggle over a gun; the firearm went off as Prince was trying to take it away, and the other woman’s boyfriend was killed. Prince, a Black woman, ended up pleading guilty at the advice of a white court-appointed lawyer who met with her for no more than 15 minutes. Although she thought she was pleading to involuntary manslaughter, her plea was for murder and she was given a life sentence. As part of a rehabilitation program, Prince applied to work at the governor’s mansion. Rosalynn Carter immediately hired her to care for the first couple’s young daughter, Amy, and Mrs. Carter was convinced that Prince was innocent.

After Carter’s term as governor ended in 1975, Prince’s work release ended, but Mrs. Carter continued to visit her in jail and at a later work release site. Prince was allowed to attend Carter’s 1977 presidential inauguration, after which Rosalynn offered her a job in the White House. ‘How would you like to work in this big old place?’” Prince recalled Rosalynn asking her, according to People. In order to make the arrangement work, the new first lady wrote a letter on Prince’s behalf to her parole board, which secured to her release and resulted in President Jimmy Carter serving as her parole officer while she worked in the White House. The unusual arrangement ruffled some feathers; Saturday Night Live even spoofed the situation in a 1977 skit, with Garrett Morris appearing in drag as Prince, “the ex-convict from Georgia.” But the Carters did not let the criticism deter them from advocating for Prince, and Mrs. Carter and Prince remained friends. With the Carters advocating for her, Prince eventually received a full pardon, clearing her record.

After the Carters moved back to Georgia upon leaving the White House, Prince bought a house near theirs. She continued to visit them and she also would babysit their grandchildren. She maintained her friendship with Rosalynn. Author Kate Andersen Brower interviewed both Rosalynn Carter and Mary Prince for a 2015 book, The Residence: Inside the Private World of the White House. Carter reiterated her faith in Prince’s innocence. “She was totally innocent,” Mrs. Carter said, according to WSB-TV. At the time of the interview, Browser noted that Prince still lived a few blocks away from the Carters and was now babysitting Amy’s son, Hugo. Decades after their first meeting, Prince was “still a huge part of the Carter family,” Browser noted, per C-SPAN. “They consider her one of their own, and they just love her.” Now, the Carter family, Prince included, are left to mourn and remember Rosalynn.