More Of A Long Question...?

Ok so this is my first of many confessions and it is a little hard to explain. She is not blood but has been raised as my cousin.

Basically she called me one night and told me her boyfriend had been beating her, i naturally broke more then a few speed limits, arrived and hospitalised him. After i got released by police (the guy refused to press charges for fear of the truth coming out, that he had broken more then a few of her bones) anyway. A few weeks later she called me and said he was outside again, i got there and this time i kept my cool, he 'slipped repeatedly as i tried to help him up and ended up breaking his jaw, leg and one wrist' (is what the official police report says) i was still helping him up with my fist as the police turned up.

Since then she has professed her love for me and wants me to go out with her. She is hot and we get on so well but we were raised thinking we were cousins...
She is 19 i am 25

I know rationally she is just seeking my protection, which she will always have free of charge, same as any women would.

What should i do?
zaketh zaketh
26-30, M
Aug 1, 2013