Hey there Richard,
Welcome to planDisney and thank you so much for your question! I'm thrilled to hear you're planning a trip with your grand daughter. You are all are going to make such magical memories together!
It sounds like your grand daughter is in a sweet spot in terms of her age! There is plenty to do around the Happiest Place on Earth for Guests of all ages, but I particularly love the 7-10 age range for kiddos because there is so much to do, see, and explore.
My recommendation for you all would actually be to consider purchasing the
Park Hopper option for your tickets. With this option, you select a park to start your day in then beginning at 11:00 AM you can hop between both parks. I love this option because it adds so much flexibility to your day and then you don't have to worry about picking which park to stay in for the whole day.
With the Park Hopper option, my family and I typically like to start our day in
Disneyland Park on the first day for the iconic experience of walking down Main Street, U.S.A. when you first arrive. Then my second day I would begin in
Disney California Adventure Park and grab breakfast at
Pym Test Kitchen. With the Park Hopper option, we can then switch between parks whenever we want each day after 11:00 AM.
Thanks again for your question, Richard! I hope you enjoy your visit to the Disneyland Resort.
Have a Magical Day,
Greg