Is she going to make a terrible mistake if she leaves him?

My mate hs bin maried for 9yrs wit 2 kids..the man used to beat her up whenever sh left th house without telin him,or when sh made a slight mstake..sh has realisd she made a mstke and wants to leave bcz sh has neva bin happy bt her relatives r sayin sh shud continue stayin.th guy hs promisd never to beat her again..nw sh dsnt feel a thing for hm anymor.sh's 25yrs nd man 45yrs..pls help help!