Philomena Bosco is a character who appears in the Season 4 episode of The Golden Girls titled "Foreign Exchange". The part of Philomena is played by veteran actress Nan Martin, who also appeared in the Season 2 episode "It's a Miserable Life" as Frida Claxton.
Philomena, a friend of Sophia Petrillo's from Sicily, claimed that Dorothy was really her daughter and not Sophia's. Dorothy wondered whether she was really the biological daughter of the Petrillos, since Dominic and Philomena Bosco claimed that the hospital switched babies.
However, in the third-season episode "Mother's Day", Sophia's mother is also played by Bea Arthur (though in one episode Dorothy states that her grandmother was 94 when she was only 6, though it is never made clear if it is her paternal or maternal grandmother. However she also states that she was in a wheelchair, which her maternal grandmother was.).