MS is not directly inherited and it affects people differently, meaning in severity. Epilepsy is considered remotely symptomatic among family members, but doesn’t have any influence on someone having children.
It is a personal decision to be made by the individuals. I have friends in both circumstances who gave birth to children and are wonderful parents and others who had and adopted children. Their MS nor their epilepsy interferred with them being really good parents. One friend has really acute epilepsy and another friend of mine is a great father whose MS has him refined to a wheelchair. Another friend of mine developed MS in her 20s, raised two great children with her husband and spent the last 45 years of her life with no use of her limbs. Her mind was strong enough to make up for the limbs. She was a great mother.