The Guardian

The Guardian is a 1990 American supernatural horror film co-written and directed by William Friedkin, and starring Jenny Seagrove, Dwier Brown, Carey Lowell, Brad Hall, and Miguel Ferrer. The plot follows a suburban Los Angeles couple who hire a nanny to care for their infant son, only to discover she is in fact a Hamadryad whose previous clients' children went missing under her care. The film is based on the novel The Nanny by Dan Greenburg, who co-wrote the screenplay with Friedkin and Stephen Volk.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.

Poster © the film's rights holders.