Hi From  symptoms i feel she must be having fissure in ano . Is she having this symptoms now or was it there before? Hard stools can worsen it.she should be eating lot off fibre rich foods in addition to drinking  more water. If the pain is severe she can consult a surgeon  or else sit in a basin with warm water to relieve pain and apply some antibiotic ointments. However these are temporary measures so consult surgeon and modify your diet. Hope you are convinced. Best wishes