There Was a Little Girl

Madhouse is a 1981 slasher film directed and co-written by Ovidio G. Assonitis, and starring Trish Everly, Dennis Robertson, Allison Biggers, and Michael Macrae. The plot follows a schoolteacher in Savannah, Georgia being stalked by her psychopathic twin sister in the days leading up to their birthday. The film's original title takes its name from a poem called "There Was a Little Girl" by Henry Wadsworth Longfellow.

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

Poster © the film's rights holders.