Recovering Anorexic & Pregnancy?

I'm 4 months post. My partner wants to carry our next baby, but I'm worried. She's in her late 30s and has been anorexic since childhood. Her recovery started after we met a few years ago. Whilst she is moderately healthy now and at a safe weight, it is a daily struggle for her. So many years of an eating disorder has taken it's toll on her. She had multiple miscarriages due to it before we met. I'm afraid she will be unable to carry to term safely and of how she'll react to the body changes. We've talked about it and I've expressed my concerns, but she's determined. Docs are no help "won't know if she can till it happens". Any advice would be greatly appreciated. sorry for the long post, just at a loss here.