I just found out my daughter is in a poly triad relationship?

I agree with Anna you should be happy that you have a good enough relationship with your daughter that she has confided in you to share this with you. You may not want to hear this but she is an adult entitled to make her own decisions. This is not about you nor is it about your ability to be a parent. Instead this is about her and her choice. Living this type of life has no impact on her ability to have a career or have a family. If this is the life she has chosen for herself then she will accept the consequences of that decision. The best thing you can do, in this situation, is to be supportive of your daughter and not be judgmental. I believe in time you will come to accept it and it will be easier, I feel, by being accepting of the choice.