Well she offered to pay you, thats still cool. Sounds like she didnt try to come at you with a ice pick or hammer, just a polite business request. Gotta respect that at least...
I am personally willing to deal with those that treat it like a business and do not try and get all personal. If they offer me a fair price sure I will deal.
If at all possible, keep her on your good side and say you will knock of x amount for each girl she sends your way that you shoot.
Often these girls know other girls and well....