They are a bit young for for ovarian cysts, to be honest. These are more frequent in older sows. You would have to see a vet over them. Larger ovarian cysts can be felt, but it is more frequently the small, growing ones that can cause the hormonal/aggression problems. The majority of cysts are not causing any problems, and you do often not ge the full set of symptoms, if any, like thinning hair on the sides or crusty nipples.
Is the bickering on a daily basis or is it an off-on whenever one of them is in season? is it one girl that is causing it or are both doing it?