Hello Deborah!
You and your granddaughters are sure to have an amazing time experiencing Bibbidi Bobbidi Boutique! It is a strict requirement that little princesses be between the ages of 3 and 12 years old. Based on my own experience, the Fairy Godmothers-in-training will likely also interact with the little ones a bit. I can not make any assurances that this will be the case for you, of course. Fairy Godmothers-in-training are not permitted to perform any services on Guests under the age of 3, unfortunately.
I may have a solution for the little one, however. There is a special little place located at the beginning of Main Street, USA in Magic Kingdom Park called
Harmony Barbershop. Guests of ALL ages are welcome. There's even a first haircut package which may be of interest to you? Regardless, your granddaughter can have Pixie dust put in her hair. In addition, stickers and bubbles are usually part of the mix. Be sure to call (407) WDW-PLAY to book!
I wish you a truly magical vacation.
-Jacqui