Housecleaning Prices?

Hi everybody! I have been cleaning houses on my own for a while now. I consider my prices pretty low considering everything I do. I’ve never had a client negotiate the price before so I don’t really know how to proceed or counter it. I was charging her $145 for a 2 story house with 4 bedrooms and 3 1/2 bathrooms and it included doing the dishes and washing and folding sheets and towels. She wants to pay $140 for what I mentioned and wants to add her back porch as well. Is this a reasonable price?