She will adjust to the new schedule and be secure with it soon, dogs don't like change and are not great at it, however if it becomes routine and a familiar she will learn to accept it just like she did learning feeding times, bed times ,exercise schedules etc. dogs thrive on structure.
Make sure you exercise her well by letting her run and play catch in the yard before you take her to mold, have a pup icee of worn clothing with your scent when you drop her off, her blanket, a couple toys and her eater bowel. These things are familiar to her and helps accept the new change, in her ,info if her things are there and your scents there she must belong but at first dhes unsure where.
It may take a month or so depending in her socialization level and how ,any new experiences she's had and how long it takes to adjust. Pretty soon when you day time to go to grandmas the dog will be exiting at the door wanting to go, no separation anxierpty.
When you wave her, reassure her you will be back, but don't user fuss over her. I usually tell my dogs, be good, have fun, I'll be back later today and simply leave. At first they tan for the window and whined, but I came back every time I dropped them off, praised them and made a fuss of how good they were. Usually about two weeks into it they were in their new routines.
If you don't fuss over the dog and worry about her anxiety etc or really
care what happens, you can have a sog that ends up suffering from separation anxiety or later. Down the road behavioral issued , fear of windy days, storm phobias, running having blind terrors running into doors, eindoed etc every time one of het family leaves the room (in bad cases). It's better to train the dog and acclimate it especially this late in life. Making sure the dog doesn't go nuts isn't over fussing, not going to work would be.
Too many prope eould simply shove Fido out in the yard, lock it in the bedroom or basement and just think all will be fine, they don't stop and think hoe hard it is on the dog . Imagine living in one place your whole life then suddenly wake up in a new country, new language, new foods and customs... would you feel stressed out or confused or bewildered as to what to do, what happened and where did family and home go. That's how a schedule change can affects the dog.