I think the the Grand Floridian might be the ideal spot for a grandmother/granddaughter trip.
Things to consider
1) You two can go to “high tea” in the lobby. The Tea event is pricey but gets good reviews. There might be one seating that is friendlier to kids.
2) Go to a character meal at 1900 Park Faire. I think it is a Mary Poppins theme or a Cinderella theme depending on which meal you go to.
3) Two great pools. One has a great slide feature that kids love.
4) There is the Royal Princess Parade, led by Cinderella and Prince CHarming. See this post.
https://www.disboards.com/threads/t...t-disneys-grand-floridian-resort-spa.3493412/ But be sure to check on the dates it is offered. It is no longer available every day. Check with the concierge desk to find out when it is running.
5) Ride the monorail. You could visit the other monorail resorts, go shopping, etc.
6) Narcoosies is a very nice meal. If you stay until the time of the Magic Kingdom Fireworks, you can walk outside to the dock outside Narcoosies and watch the fireworks with the music piped in.
7) If you are comfortable with boats, you can rent an inexpensive pontoon boat and explore Bay Lake and 7 Seas Lagoon.
8) Grab a chair in the lobby and listen to the Grand Floridian SOciety Orchestra, which plays in the lobby. Your granddaughter might prefer to watch them from the railing of the 2nd floor so she can watch the musicians play their instruments.
9) If you don’t want a deluxe restaurant, go to the Quick Service - Gasparillas - You can watch the fireworks with music from here, too.
Have a great time!