Getting Too Big For The Cat

Our poor little kitty is the target for Molly's need to wrestle. It was fine a few weeks ago when they were the same size and she could easily jump out of Molly's reach. Now, kitty gets pinned to the floor with her side held firmly in Molly's mouth. I break it up as much as I can, but the dog can reach kitty everywhere but her cat tree, top of the gate to upstairs and if she is on the table, which I discourage. I know for sure the cat is unhappy with Molly's presence and now avoids her instead of the taunting she used to do. I was hoping they would be friends, but Molly's desire to play with absolutely every one and thing she meets needs to subside before this can be.