I never heard of either one!
Well in the US I think it was released as "Girly" but it was directed by top cinematographer Freddie Francis (who though responsible for such direction like The Skull was guilty of Joan Crawford's dire Trog) and is a cross between "The Old Dark House" and Joe Orton. I figured it was going to be obscure and only recently managed to see it myself. Thanks anyhow.
Look for Maisie Mosco. Shelfari itself says that "Mumsy, Nanny, Sonny And Girly" was based on a play by Maisie Mosco.
Yes. Thanks. It did look very stagey hence the Orton comparison. They really should do an up-to-date of "The Old Dark House" seeing that was based on a Priestley novel - Whale good Hammer not.