That sounds very frustrating! My thought is that your daughter has been through several big transitions in recent months. It's been quite a lot for you and certainly for her. What you describe is how my child has responded to "stress" in his life at ages 5 and 6.
My gut is that she is having trouble unwinding from the intensity of her full day experience. I've seen that repetitive behavior from my child when he is "burned out" and trying to "numb out" ... plus it can be fun to annoy your mother for some negative attention when you have missed her from being away from home all day.
We had success with doing therapeutic things like roll him in a blanket and press on him (pretend he's a hot dog or taco or burrito and put on different toppings) and swinging. There are great activities like those in the book The Out of Sync Child Has Fun.
Go with your gut of course. You will know what rings true about what you are seeing and what doesn't. My child does have sensory issues but the calming I saw with the activities I mentioned above was downright shocking. Hope you find answers (and peace at home) soon.
