Since a year we have a second cat, male -but "helped"- and that one sometime sits on top and pushes her to the floor for 30 seconds. She can't move and makes weird noises. Maybe she's stressed out because of all that?
Yeah, they often turn proud cut, especially if neutered late. My boy wasn't "helped" (he's not a breeding cat, but I just didn't have the heart to do that to him!), but he doesn't cause any trouble. The vet thinks it's because I spoilt him rotten. He sometimes annoys his sister and she indeed tends to hide from him by my side (she's smaller than he). If you are the one chasing the other cat away from her, she may like to stay close to you and those looks are to express her gratitude and trust. She looks healthy and nice.