There is 100% chance of getting F1 visa if she is qualified. Consular doesn't care about family (either they are murdere/terroist/etc/etc until unless he/she is Internationally known) background and she doesn't need to provide all the family documents to consular. Only things here matter is how qualified is she (how strong is her education background, what is her field of study, what is her TOEFL/ACT/SAT/GRE/GMAT score etc), what is her background (is she govt employee, is she working at some reputed organization etc). Consular very rarely ask about hers husband/parents (what they do, where are they, what is there income etc etc). If they ask, she doesn't need to disclose (but if she gets visa and arrive to US, then at Int Office, she need to give exact info). Her father or father in law could write sponser letter.