My 14 yr old can't stand her father and loves her brother more than anyone....?

She has always avoided my husband and clung to her brother all the time.My son is 9 years older than her.She can't stand her father at all and I have no idea why it's been going on since she was about 3.She became close to her brother at 4.She doesn't want her dad touching her at all.When it's her dad she'll cringe and she won't show affection to anyone but her brother (who is a dropout and lives with us.) I have asked her several times if my son or husband has ever done anything to her and she said no...what to do??