Hi there! I've been lurking and, I have to say, I wish my dh was half - even a third - as romantic as you are. She is a very lucky girl to have you.
The mall is a great place to get some outfits but also Target is absolutely fantastic to get stuff that's not too expensive. Think Wal Mart gone chic. Target is pretty much every American's favorite all around one stop shop. Wal Mart is where we buy essentials - groceries, plain tees, socks, lawn care, etc. Target's where we go for cute clothes and shoes when we're on a budget- or rather - when we want to "load the cart up"! The clothes, shoes, bedding, etc are lines by famous designers. Think fashion for the masses. I'm not sure where Target is but it's a good bet there's one pretty close to WDW. Probably near the closest Wal Mart - being each other's competition and all.
Also, I know for me personally - although I love all the planning that goes with a trip to Disney - if I were in her shoes, I would looooove a big surprise at the airport. Sure, I would worry about how much I packed but if I knew
I was getting to shop I'd be a happy girl! Good luck!