Right of Way (1983)

Miniature Dwyer is named after her mother, who was making miniature doll houses when Minnie was born. Minnie, too, has built doll houses for years, and when she learns that she is terminally ill, she and her husband Teddy begin planning their joint suicide. She makes sure that her dolls are placed with people who will appreciate and cherish them. The couple refuse to allow their grief-stricken daughter or the solicitous social worker or anyone else to forestall the death they are determined is right for them

Unfortunately the movie Right of Way is not yet available on HBO Max.