Oh now that is just adorable. Is this your own pattern or one that you purchased? Very cute! I think that inner pink accent border is just perfect...it really pulls the pink out of the other fabrics in your top. :) Everyone's taste is different, but I think your normal size binding would be just fine. (I like a narrow binding myself.) I would even switch it up, since you've got so many colors and maybe bind it in one of those bright blue's or green's you've got in there.
Whatever size binding you decide to go with, I would think you would stop at that same (finished) measurement at each corner as you go around the quilt folding your binding down. I haven't played around too much with different size bindings though, so this is just a guess! I'll be anxious to see what advice you are given in that regard. :)
Can't wait to see how you decide to finish! :)