16 year old kids tend to go off about anything that they don't think is like what everyone else has. They are hyper-aware about what is "normal" and desperately want to fit in. I remember at that age being so angry with my mother for her being a stay at home mom and not like all the other moms I knew who went out and worked. What I'm trying to say is that it doesn't matter who you are or what you do teen minds tend to warp things and they will likely find something to be unhappy about. It will pass. If she knows that she is loved and accepted for who she is. The anger about your polyamory probably won't even last that long.
I also saw in your original post that you and your husband are getting divorced. It sounds to me that she is angry about that more than about who you are with at the moment. I think it would go a long way for both you and her dad to talk to her honestly about why your relationship didn't work out. It might help to ease the blame because it sounds like she is blaming you in a round about way for her family being broken.
Everything will be ok in the end. If it's not ok it's not the end.