Hi Judy,
Welcome to the Disney Parks Moms Panel and thank you for sending us your question. My daughter is 9 as well and still loves wearing her princess best while on vacation at Walt Disney World Resort.
I love walking through Magic Kingdom and seeing all of the princesses walking around with their parents. There are always lots of older children dressed up so I definitely do not feel like 9 is too old for wearing a costume, especially if she is planning on visiting the
Bibbidi Bobbidi Boutique. In the end, depends on your granddaughter and her comfort level, but we have several friends who have daughters had originally not planned on dressing up, however once they arrived at Walt Disney World Resort, changed their minds and decided they wanted to wear a princess dress. My daughter still loves dressing up and will have a different princess dress for every day of our trip. The past few visits she has been a little less adamant on packing her really big princess dresses and is now having fun putting together princess inspired outfits.
If your granddaughter is hesitant, perhaps she could dress up for her visit to the Bibbidi Bobbidi Boutique and your meal at Cinderella's Royal table and once your meal is finished, change into something more comfortable. The Bibbidi Bobbidi Boutique offers several packages that will suit the personalities of most. Another suggestion would be to visit
The Pirates League for the Mermaid Makeover, which is slightly more "cool" according to my 9 year old.
I hope you enjoy your time at Walt Disney World Resort, Judy. Please let us know if you have any other questions, we are always happy to help.
Stephanie