LORELAI: Alright, I’ll name him. [to chick] Hi! Your name is Stanley. Hi, Stanley.
RORY: It’s a girl.
LORELAI: Oh. [to chick] Sorry about the Stanley thing. Your name is Stella. [to Rory] Stella’s nice, and Stella was married to Stanley.
A reference to the 1947 play A Streetcar Named Desire by Tennessee Williams, earlier discussed. In the play, Blanche DuBois’ younger sister Stella is married to Stanley Kowalski, a factory parts salesman.
A Streetcar Named Desire was highly successful on Broadway and in London’s West End, and won the 1948 Pulitzer Prize for Drama. It is regarded as one of the greatest plays of the twentieth century, and is Williams’ best known work. The roles of Stanley and Stella were played by Marlon Brando and Kim Hunter in both the original Broadway production, and the 1951 film version.
I think Lorelai is saying the name Stella is nice, rather than the character, but can’t be quite sure.