My teenage daughter is withdrawing because of a new baby on the way. What do I do?

I have always been exceptionally close to our daughter (14,f). However, I notice her withdrawing from me more and more the further along I am in my pregnancy. She is still talking to me about boys and stuff going on at school. But she's very unemotional and uninterested in the baby. We know it's somewhat crazy to have children with a 14-15 year age difference but we are just trying to focus on being good parents, in general. When we first told her about the pregnancy, she was dead set on having a gender reveal and even though I didn't want one; we decided to do it. We thought it may be a good way to foster some excitement and goodwill towards the baby. We found out yesterday that the doc has the results. So, I excitedly texted her and her response was cool. Turns out, she no longer wants to do the gender reveal. We prodded to make sure that it wasn't a logistics issue, she just isn't interested. Lately, she just seems uninterested in the baby. I don't want to push her away and force the issue, however, I don't know if NOT discussing it is worse. I know that being 14 is tough and it's understandable to have some unhappy feelings about a new addition. I just don't know if there is a point I should intervene.​Edit: Her father and I are having a new baby and were recently married. But, yes, he is her bio dad. via /r/Parenting https://ift.tt/2K5TiVU