Does molly mean princess

No. "Molly" is a form of "Mary", which means "bitter" or "bitterness". The meaning comes The Bible, in Ruth, 1:20-- "Call me not Naomi (the pleasant), call me Mara (the bitter), for the Almighty hath delt very bitterly with me." "Marah" was a Hebrew Word for myrrh, and it also honors the Virgin Mary. It's also supposed to suggest a girl or woman who wouldn't want to be named an ordinary name for girls, because most girls' names mean things like "pretty" or "graceful"; she would want something humble and modest.