Sick of the cold shoulder?

So I've been dating this woman for a couple months now . . . things were going pretty well until last week, though she's refused to commit I've been ok with that. All of the sudden she's being a total ice queen, ignoring me most of the time, being all snide and sarcastic and critical when we talk. She says she's in a bad mood and doesn't know why. I've done nothing but treat her like a princess and she has no excuse to treat me like this. I have too much respect for myself to let her walk all over me. Should I ditch her or give her some time to figure out what her problem is? She's already said she doesn't believe in marriage or even living together, seems all she wants is FWB, and the isn't even that good or frequent!