cellio | daf bit: Bava Batra 109

From a mishna about inheritance, the g'mara discusses choice of a spouse. R Eleazar says: one should always cling to (associate with) good people. From Moshe, who married the daughter of Yitro (a Midianite priest and thus an idolater) descended Yonatan (an idolatrous priest, according to a note). But from Aharon who married the daughter of Aminadav (a righteous person) descended Pinchas (also a righteous person). But the g'mara is not satisfied with these examples for various reasons, and Raba says: he who wishes to take a wife should inquire about the character of her brothers. We learn this because the torah says Aharon took Elisheva, the daughter of Aminadav, the sister of Nachshon (who was the first person to step into the Sea of Reeds, trusting God). Why would the torah tell us she's the sister of Nachshon when that's obvious? To teach Raba's lesson that the character of a brother is an important influence. (109b-110a)

Modern me would like to believe that all of this is in addition to the woman's own character, but I'm not so sure that's what the rabbis here meant.