I recently slept with a girl and she told me that I was hung like a Jew? WTH is that supposed to mean?

In my experience, Jewish men are above-average endowed.

FTW.

So I suggest you just decide to take it as a compliment.

Yes

sounds like she was trying to hit your ego and make you feel bad, I would ignore it, chalk i up to experience,don't see her again, people like that have poor self-confidence and very poor self-esteem and they have to hurt someone else because of how they feel about the world and themselves