Did you ever find out what is going on with your female Betta? I have a female, same problem. I saw your pictures and thought it could be the same fish, just different colors! Mine has a white spot near her anal area, like an egg spot, but it has been there for more than two months and she is absolutely HUGE! I have tried fasting and peas, everything that I can find! Her water quality is excellent, in a 5 gallon tank with two snails and her Purigen filter keeps her ammonia, nitrites and nitrates at near 0 with 25% water changes every other week. She seems healthy and happy, inquisitive and energetic. She is just so BIG. I am hoping you found out what is up with yours, maybe the same thing is going on with mine..