[TheNewGirl]

Or she has no sex drive, or she doesn't know her body well enough to know how to enjoy sex. These are very, very very common problems.

Furthermore she could have a medical issue (I once switched birth control to one that absolutely obliterated my desire to have sex and it ruined a very long relationship).

But at the end of the day those things are her responsibilities, and if your desires for sex don't match up you're not a good match and that's a deal breaker. Get out before you end up in a sexless marriage and cheating because any 'change' she makes now are unlikely to be long term.