Is there a natural cream instead of Premarin?

Mom has not a prolapsed uterus but a weak vaginal wall. The specialist suggested Premarin. Not only is this drug-cream have dangerous side effects, but it is made from horse urine and is cruel to animals. Also, my aunt died of cancer after taking it. Does anyone know of a natural form?
Is Estriol a safer way to go?
It's so frustrating that doctors don't give you options. Premarin is $200 a tube!!