Dear Mayida-
Welcome to the group!! My name is Courtenay and I have thal minor. I didn't have any trouble conceiving my children...Does your niece have Thal Major?
Im sure your niece is under the supervision of a high risk ob, or a neonatologist with her needing fertility treatments. As long as she is having her blood levels monitored (iron, serum ferritin, Hb, and hematocrit) and her spleen size and liver enzymes, she should have a healthy pregnancy as long as shes a minor with no other muted genes.
If she's a major, I'll let the other Thal Major mommies on this board take over! There are so many other issues that come into play then.
Courtenay