It's actually kind of funny how many people think Lee and Clemmy have this tight knit bond that'll bring them through the apocalypse unscathed. I've never actually looked at Clemmy to have that sort of bond with Lee.
At the moment, Lee is her caretaker, if anything. Of course they're going to have a bond. She's probably scared out of her gourde. Children have the tendency, especially if separated from their parents, to attached themselves to an authority figure until they're reunited with their parents. I've actually considered that as an ending. Her parents are alive and she departs with them, leaving Lee all alone... again.
Hopefully that's not the case, but I've always wondered why she wasn't a little more rebellious in some circumstances. With her wanting to find her parents, no matter what Lee says, I found that to be a proper response. Now we just have this asshat on the radio, effin' with us.