eeh. if she always responded a few hrs later, i would've taken that as a sign of not being that interested. or not being interested in anything other than friends.
maybe this girl has trouble being assertive or, again, just wanted to be friends so she kept chatting. i don't know, but yeah, it really is good it happened only 4 months in.
i'm sorry you got your head and heart messed w/, though. i know that's not pleasant.