New Baby, Small House!! Blended family

Me and my fiance have been together for almost 3 years. Coming into the relationship I had a now 9 year old and he has a 15 year old. I have my 9 year old full time and his 13 year old would come over on occasion. My fiance owns a 3 bedroom mini home. His daughter has always had the bigger of the 2 extra bedrooms. When we moved in my daughter moved into the smallest room. His daughter is welcome to come anytime. We often ask her to do things with us but she tends to want to stay either at her mothers house or my fiance's parents, who just live up the street from her, spoil her rotten and have done a lot of the raising of her. She may come and stay once every few months but only if she has a friend with her and they stay in her room the entire time. It has been hard to make a connection with her but that is another issue completely. The issue right now is that I am currently 25 weeks pregnant. We have no place for the baby. We are searching for a bigger house but it isn't going to come fast and things take take. We have no storage or anything really. My fiance talked to his daughter about letting my daughter move into her room until we find a larger place and she was fine with it at first. Took her bed out and was prepared to move the rooms. Now she is upset and doesnt want the room taken away. Even though it is temporary and she barely uses it. She has 2 other bedrooms at her other homes aswell. Is it selfish to expect that for a short time she would be without a room here? I am feeling very guilty about the whole situation but we have no space! And moving to a larger place is going to take time.