Depends on the area of the country. In the south, yes. In Colorado, no. It means: "She does not have" or "she doesn't have"

Ellis: "She ain't got" is demonstrative of poor grammar. One has to be careful of popular music, because some of it it not demonstrative of a good grammatical usage.---Warm Regards, Bruce

Spencer is right, it means "she does not have". It is very informal and generally is only used when speaking with close friends/family or in song lyrics. I live in the Southeastern U.S. and occasionally I hear people say that.