hello my first impression is that she should not conceive while taking anti epileptic drugs...coz various adverse affects occur in mother and child pregnancy itself may precipitate seizure....and she has to follow strict antenatal care..... but not with phenytoin coz a dangerous syndrome known as foetal hydantoin syndrome occurs in which the baby will have craniofacial and limb anomalies and also will have low iQ so its bettr to change this drug if u are planning to conceive on above mentioned risks kindly contact neurologist and obstetrician and proceed further.