First of all, I love your quilt :) Here's my opinion....add another border but not the butterflies (you could use that for the backing maybe :)). The second border should enhance the body of the quilt and not distract you by drawing your eye away from the quilt itself. Whatever green is in the body of the quilt would make a lovely contrast with the pink and make it "pop" a little but not overwhelm. Be sure to show us what you decide on.