Potty Trained????

I have been trying to get Kara potty trained since she was about 18 months old. Two months ago after a intense time of trying to force her, I gave up and decided to let her set her own timing. Yesterday just out of the blue she came up to me and told me she had to go potty. After she went potty I asked her if she wanted her diaper back on or her new Curious George underwear (Christmas present). She choose the underwear. She stayed clean and dry all day yesterday, and all day tonight. Her pull-up was even dry when she woke up this morning. The question on my mind now is, has she finally decided to be a big girl, or is she going to wake up in a day or two and decide to be a baby again. (Previously when we were potty training she would tell me she was a baby). I guess only time will tell.