a hundred different reasons
sometimes she pities the abusive guy

and think she is the only one who can save him
because no one else will do it
sometimes she has no earning power

or is too lazy to work an actual job
so she takes the beatings because it is path of least resistance
sometimes the abuser is a master manipulator

has her mind coming and going
because he knows exactly what buttons to push and when
sometimes she has a warped view of reality

and every man she has known is abusive
so she doesn't know any better
sometimes she is religious or kids are involved

and she wants to stay together no matter what
to avoid stigma of being divorced or a single mom
and sometimes she is simply a demonic piece of shyt

like that woman who dated a registered sex offender on purpose
then encouraged him to fukk her 4 year old daughter in the ass