Amy, I've been taking a peek at your site and seen your progress. It's coming on! I have a suggestion for your tree background: Reduce the file size (=quality) in order to make it load faster. It took 9 seconds for it to open with my internet connection, and I have a fast one.
I have attached a version of your banner with a transparent background, also around the logo. You can use it if you want to get rid of the white square.