Polygyny is what she really means. One man married to multiple wives. Polygamy is a mishmash of anything.
https://news.google.com/news?ncl=dwS4cRTCoKhTHVMFcgMhPp-B0Dk8M&q=Polygyny&lr=English&hl=en&sa=X&ei=wSAnVMOIMtOqyAT7pIK4DA&ved=0CCMQqgIwAA