While you're out picking up foods, get some baby food. Chicken, turkey, sweet potato, peas, and carrots are all good ones to grab. Also stop by a pharmacy and pick up some needle-less syringes. Hedgehogs that haven't been eating for a few days are already not well off. Once they stop eating, their organs can kind of shut down, and they're going to feel crummier, so they're hard to get started eating again on their own. You're going to need to syringe feed her. Baby food is a great way to do that for a short time. You'll want to syringe her water as well since she's not drinking. Just try to get as much as you can in to her. There's more information & tips on syringe feeding here - https://www.hedgehogcentral.com/forum...ng-sticky.html
When you first noticed her looking odd, was she cold at all? Or did she seem perfectly fine other than the lack of eating/drinking and activity?