It's not much.  In fact, it doesn't really seem like it's much at all but it is.  It's more than she has given anyone else because she's not good at letting anyone in, just in case people haven't noticed.

It's a key to her new home.   It's pretty much permission to come over whenever he wants.

♥ I SEE L O N D O N I SEE F R A N C E ♥
UNDERWEAR MEME