@Changedmymind99 - Get her out of your life. I know it's hard to do but she is using your DD to show off. Others will think she's a doting DGM.
My DM showed off about my DS but she had no input. Others would just assume she had like normal DGMs.
My DS went to a private school that I paid for. She didn't contribute at all even though I was a single parent. But she bragged. He didn't want to do sixth form there so he went to a selective state school. Her take was I should make him go back (I'll get right on that, he's 6ft 1 and twice my size and he would refuse to go) and it will take her time to get used to it (it wasn't happening to her and she'd never even seen the school. She also hadn't seen my DS for 6 years). What she meant was she couldn't continue to brag that he was at a private school and again, yet again it was about her.
My DM was equally ungracious when treated. My DF paid for our dinner long after they were divorced and she didn't even thank him. We paid for lunches all the time for her, again no thanks. Because she believed that she deserved it. When we couldn't continue to take her to lunch during a difficult patch she became vile and even more spiteful. She didn't pay for a lunch, of course not. Because she was special.