Don't be too shocked if she backslides now. I wouldn't have been surprised from her earlier behavior if she'd acted distant again in the morning (it's great that she didn't, but it could still be coming.) But even if she does, treat it like a temporary setback. You're accomplishing great things.
This looks to me like she's been showing you all her fear, but not all the thoughts and spinning wheels in her mind. I doubt she just suddenly decided to kiss you. All that work you did that felt like banging your head against the wall was getting through, she just wasn't ready to let you see it.
