I agree, she needs to ask her doctor about this. No one on here knows the cause, if anything, of her murmur. Usually when a woman has a heart condition/disease that is severe, the doctors will tell them right away that children are out of the question. None of this even becomes an issue.
She really needs to speak with her OB-GYN and cardiologist about this. I would also meet with a geneticist to determine what your children's risks would be.