she has millions more than you in assets at 18 years old.
A Gentile girl or woman, especially one who has attracted a Jewish man. The term derives from the Hebrew word "sheketz", meaning the flesh of an animal deemed taboo by the Torah. Since a Jewish man marrying a non-Jewish woman is taboo also, this word applies to her.
Traditionally this is a derogatory term, though in modern times it has also been used more light-heartedly. For example, Seinfeld once did an episode about Elaine's "shiksa appeal".
The ideal shiksa is a blonde WASP who look like the opposite of a stereotypical Jew, but in reality, many shiksas are brunettes who might pass for Jewish themselves.
On Sex and the City, Charlotte really blossomed as a shiksa!