Hi, Christina! With three daughters, I can't tell you how much I truly enjoy taking some time out for each one and doing a Mommy and Me trip - and 14 is an awesome age to do this!
In addition to all of the obvious things to do, among the things my girls and I love is having tea at the Grand Floridian. You can make a reservation by calling 407-939+3463. It's such a "girly" thing to do (although I've also taken my husband and father-in-law, and they love it!), and it's a nice way to bond in a bit more laid back environment than a regular theme park restaurant. The food is just wonderful, and it's a relaxing afternoon bonding with your daughter.
You could also consider a spa treatment while you're there! You'll find spa facilities at three locations at Walt Disney World, and even if you just go for a manicure and pedicure, it's relaxing and revitalizing, and a great way to share time with your daughter. You can find more spa information by clicking this link
Disney World Spas.
For something completely different, you can take your daughter up in the Characters In Flight Hot Air Balloon. The 15 minute balloon ride will give you a view of the entire Walt Disney World area, and is just a darn cool thing to do.
Other things I've done with my girls include getting temporary tattoos and hair wraps, getting dressed up for dinner at Citricos at the Grand Floridian, and sharing a turkey leg while watching the parade at the Magic Kingdom!
I hope you have a great time with your beautiful princess!