Suggest Treatment For Heavy Menstrual Cycles

My sidter's been having heavy menstrual bleeding w clots for over a year now w no diagnosis. A few months ago she required a blood transfusion. She has had nothing but a week or two of no bleeding between bleeding periods of a month or so at a time. She's homebound during these times because she has to change pads so frequently and sometimes wears 2 overnighters. She is obese, 38 y/o, hasn't had sex for over 4 yrs. She has two children. First a c section and the other a vback w/o complications. They've told her she has fibroids but apparently nit significant enough fir any procedures and has only been told she may want to consider a hysterectomy which she prefers not to do at such a young age. What could be causing this.