Both are just over a year old and went to the vets this August. They were given the all clear but obviously things can change during that time. I have however been checking them regularly for any lumps or bumps. I will though be taking them to the vet again soon just to make sure because one of my pigs does have a fungal strip that needs treated.
No, it doesn't sound like ovarian cysts but rather like a long-standing sibling rivalry that has flared up due to teenage hormones.
In my own long term experience with quite a few sisters (pairs and trios), the end of teenage ca. 12-14 months is the worst period where the girls are constantly scrapping outside of when ovarian cysts and nonstop high hormones come into play with some of them. They may or may not go back together.
What is difficult for us to judge is whether your two are constantly just at the limit or whether things have tipped over the edge. You will have to see and take it from there.