Should I Fileng jointly or separately for the taxes?

I have a W2 and also studied 2 semesters last year (I'm not taking cles this year) my wife is a self employee so she has to pay taxes at the end. Probably if both were on w2 it would be better to file jointly. If I'm a W2 and she is self employee, is it better to file separately or jointly. Would we get more if we do it separately?