Hi, Katy!
A Disney Gift Card is another great way to bring funds with you to the parks. We actually like to let each child have his or her own Gift Card, so that each one can budget souvenir purchases more concretely.
In order to determine if you should bring a Disney Gift Card with you on your upcoming trip to Walt Disney World, check out
this link to Disney Gift Card's website, which will detail locations at which you can use this card. One word of advice regarding your dining reservations: the website specifies that you can use these gift cards at Walt Disney World Theme Parks' Disney owned and operated dining locations. Thus, if you have a reservation at a dining location that is not Disney owned and operated, you may not be able to use this gift card there.
Don't forget that you have the ability to charge purchases and dining to your Key to the World Card at many locations, too. We take advantage of that, too, and settle up at the end of our stay with a credit card.
Send any more questions you may have as you think of them! I'd love to help make this as flawless a trip as possible!