Please let us know what you learn from other consultations you are able to arrange.
I'm glad that your son is OK. As I'm sure you know, a fraternal twin would make a great transplant donor, if only your daughter was eligible.
If you and the psychologist think it would help, you could try and connect your daughters with other teens facing serious illnesses. I've recently been looking for resources to recommend, and I learned of one just yesterday:
Ashley Jade on Facebook. There are unlikely to be other teens with your daughter's combination of conditions, but the issues that concern teens are less likely to be about the medical details than they are for parents.
To help with any issues at school, you might want to read the handy reference booklet
Supporting Students with Bone Marrow Failure Diseases from the
Aplastic Anemia & MDS International Foundation.