Hi Rachel,
At the appropriate time there needs to be conversation between you and "MOM"... First and foremost your privacy must be sacrosanct and that point must be firmly established... Secondly thank "MOM" for her role in your life... Certainly providing you with a core of good life values... Tell her that you love her and thank her for being "MOM". However your life is yours and should you wish to include her into your chosen gender lifestyle... Please feel comfortable... However... Caveat... Be honest... Time permitting MOM will accept her daughter...