LizKaren,
I too have had these problems growing up too. I had a span of having 3 periods in a month and then going a total of 4 months without a period at all. It was very frustrating for me, but it eventually worked out in the long run. I’ve never had good cycles and whenever I had a period I would always have bad cramps and lots of bleeding. Since I am not a doctor, I would have to agree that contacting your endocrinologist and an obgyn. I’m not really a fan of having less periods because I believe that God created a period for a reason and he gave us so many a year for a reason. To me preventing it can probably cause some serious problems in the future. But that is just me, so whatever you decide is your decision. I do agree that starting her on birth control would be a good solution considering that if given the appropriate birth control, you can have well managed periods. Good luck and I hope it all works out for you.
Liz