D.B.
First thing is don't ask her if she needs to go. Just like you don't ask a little one if they need to brush their teeth, you just tell them to go. Tell her "it's time to go potty". If you leave it up to her at this point she's just going to blow it off. This is 4 kids worth of experience talking. Almost all kids regress or get tired and lazy about it so you have to take some of the control back. DO NOT buy pull ups. You're setting yourself and her up for a long trek back to panty land. If you do that you're basically giving her permission to pee in her pants. Take her to the toilet every hour and get on the reward system. No accident's in the morning = special treat, etc.