Anyone been pregnant while on Tegratol?

I know it isnt suggested but listen to my story... I am trying to help my little sister.. She has had seisures since she was about 3 years old and is also a shunted hydrocephalic (water on brain) she was on 800 mg of Tegratol for years and lived in a haze (her words) she on her own slowly lowered her dose to 400 mg per day and is functioning much better and has not had any seisures for over 7 months.. she said she has discovered she can tell when she is going to have one and just takes the full 800 mg dose.. well she has since early teens wanted to be a mom and is now married just over 2 years and the desire has grown.. has anyone had a healthy baby while on Tegratol ( 400 mg per day) ? She was told by someone at a clinic that there may be something else she can take for the seisures that has a lesser risk of birth defects I am searching for answers for her and would appreciate help from anyone with information. She cannot go without the meds because her type of seisures can be fatal