Hi, Christina!
What a wonderful way to celebrate your daughter's 9th birthday! Great choice!
Staying within Walt Disney World is a fantastic idea, too. I just brought my 11-year-old son to WDW, solo, this past fall, and loved the convenience and safety of staying right on property. No worries whatsoever.
To make your trip the most affordable, book a stay at a Value Resort.
Disney's All-Star Music Resort will provide you and your princess with an affordable, yet fun place to call home while you are visiting WDW. WIth a mini-refrigerator in your room, you can even enjoy light breakfasts and snacks in your room, which will surely help to cut down on costs. I pack juice boxes, regular and chocolate milk boxes, plus peanut butter, jelly and breakfast bars, then pick up a loaf of bread at the resort store so that we can grab a light breakfast as we get ready for a day of park hopping. (Plus, if the little one is hungry if you come back to swim and change before dinner, you can have a cool drink and a snack in the mini-fridge, too!)
Regarding park tickets, you can cut costs by NOT opting for either the Park Hopper Option or the Water Parks & More Fun Option; while these are great, they are not necessary and are perks which can easily go unused. Just stick with the
Walt Disney World Base Ticket and you're sure to have multiple days of fun in the parks and at your resort, too.
Finally, head over to
Downtown Disney, which can easily fill a day or night with shopping and dining; there's even a bowling alley and a movie theater, too! No park tickets need, either.
Send more questions as you think of them, Christina; I'd love to help you craft the perfect birthday celebration for your princess!