Is it selfish or wrong for me to mourn?

My husbands sister got pregnant, she is young. She doesn’t want the baby and is choosing to have an abortion. But, before that she said she wanted to come live with us and we talked a lot about how our babies would grow up together and how my family will help her. They don’t have their parents as they both died when they were young so my family had basically become my husbands and his sister would be welcome with open arms as would have this baby. We were so happy and excited and supportive. Idk if someone talked her into it but she just suddenly said she wants an abortion. I’m not going to tell her it’s wrong or anything like that, but I am very upset and feel like I’m grieving for the new potential family member. I’m keeping my emotions to myself because I’m trying to be strong for my husband and for her. But, dang I’m really sad. I just needed to get this off my chest. Idk if I’ll get hate but it doesn’t really matter