Hi there, Katherine! We're so happy that you visited us here at the Disney Parks Moms Panel! It sounds like you have a trip planned to The Most Magical Place on Earth soon!
I took a look at the list of
Walt Disney World Resort Property Rules, and unfortunately, flags are not allowed in any of the Theme Parks, Water Parks, or Disney Springs. I'm guessing that you are brainstorming some ways to spot your stroller easily, which is very smart!
An alternative suggestion is to tie a balloon to your stroller handles. The Mickey "Glasshouse" balloon is a favorite souven-EAR of many Guests, and it is sure to delight your Mousketeer! They come in a variety of colors, stay inflated for several days, and you can purchase one on Main Street, U.S.A. in
Magic Kingdom Park (note, however, that balloons are not allowed in
Disney's Animal Kingdom Theme Park). My friend,
Brandy, used dollar store items to decorate her daughter's stroller and make it easy to find. If you'd like something reusable, try checking Etsy. Type in 'Disney Stroller Spotter,' and you'll get dozens of results from laminated tags to waterproof canvas fabric, and most of them can be customized with your favorite Disney character.
I hope one of these ideas helps when you come face to face with the "Sea of Strollers," Katherine!
Eean