How do.I know if a girl on facebook blocked me?

[v]

Please read all.Ok, so I sent this girl a friend request, She accepted, liked a pic of me, said hi to me first and we had a conversation, then now she's not on my friends list, but I can still see her when I search on facebook, but cant see her profile. My friend said he can't find her either and saids it deactivated, and when I send her a message it says this" Invalid Recipients One or more of your recipients are not valid. Please try again.". Did she block me?
So.it's just weird that when I type her name I can see her, but when I press on it it just takes me to my timeline, and you don't think she deactivated her account over me, she was really enjoying the conversation I could see thats then I said how's life going with her then she typed back ...hmuu?, bit you don't think she would deactivate her account because of me?