The Gingerbread House (1996)

A 10-year-old girl and her 6-year-old brother are dumped by their abusive mother and her boyfriend to spend a few days at the rambling country house of their grandfather, who has been estranged from the family for the past ten years. The girl discovers the old mans corpse in his room, and, fearing that they might be blamed for killing him, devises a cover-up plan, which is almost foiled by a local boy.

Unfortunately the movie The Gingerbread House is not yet available on HBO Max.