Hello Dorothy, and welcome to planDisney!
Oh, bother! I am so sorry to hear about the mix-up in your vacation planning.
I know that you are excited to begin your magical vacation in just a few days with your family. This is one of my favorite times of year to visit because I can get away from the cold winter weather and enjoy some time basking in the warm sunshine. This week is really busy, a lot of Guests are going to be enjoying the
50th Anniversary Celebration.
All Disney Theme Parks have limited capacity and require all Guests to have valid theme park admission and a
Disney Park Pass reservations. Once a reservation is made, it is non-transferable, like your tickets. Normally, I would suggest that your daughter and granddaughter make a reservation at any park that has an opening and park hop after 2:00 P.M. to the park you are in, provided their tickets have the park hopper option. But it seems like all 4 theme parks are booked solid for the next few days.
If you cancel your park pass reservations, there is no guarantee that you will be able to reserve them for your daughter and granddaughter before someone else grabs them. Your best option is to keep checking for availability for them daily. Other guests may have plans that change and they cancel their reservation opening up a few spots for you. I hope everything works out for you and everyone has a magical time.
See ya real soon,
Andrea