Try ignoring the accidents. Don't scold. Give a small food reward with the praise when she gets it right.
My boys are 6 and 7 and we still go crazy with potty rewards. I think that is why they always go to their pad. They do fake pees too for the rewards.
Make sure the pad is changed often enough. When Max was a pup, he really liked fresh pads. One pee and he would roll up the pad himself. Poop has to be picked up right away. The boys tell us when they need to do that, just like a strictly outdoor trained dog. If we are not nearby, Max will bark a certain way to let us know that a cleanup is needed.
Clean up the accident spots thoroughly with an enzyme cleaner so that the scent doesn't attract her to return to the spot and do it again.