This is an obscure English thriller, whose interrogative, nursery rhymesque title suggests an attempt to connect it to the series of bigger-budgeted "crazy old lady" thrillers directed by Robert Aldrich and Curtis Harrington ("Whatever Happened to Baby Jane?", "Who Slew Auntie Roo?", etc.). The old lady here though (played by Mona Washburn) is genuinely sweet, and the villains are her lazy, amoral grandson and his sexy Lady Macbeth-in-training girlfriend (Vanessa Howard). The two young people plot to get their hands on grannie's money, but rather than simply pushing her down the stairs they hatch an elaborate plot to convince her that radical youth have taken over England are planning to do away with "oldies" like her. This is thus kind of like a nasty horror version of the recent film "Goodbye, Lenin", but not played for (intentional) laughs.
This is an entertaining movie while Washburn is in it, but the other two characters are so disagreeable that it's hard to care much about them after she exits, and the young couple are also too one-dimensional to really relish them getting their eventual just desserts either. This isn't really the fault of the actors though. Vanessa "Girly" Howard is especially good(even if her failure to take off her clothes is pretty regrettable).
This movie was also probably a little too tame for 1972, even for the famously violence-adverse British, and this too might have led to it's failure and current obscurity. Still it isn't a bad movie, and deserves at least a minor footnote in the history of the British psycho thriller.