YouTube and IMDB:
"So's Your Aunt Emma!" is a 1942 American film directed by Jean Yarbrough. The film is also known as "Meet the Mob".
A dizzy old spinster gets involved in the boxing racket and gangland murders as is falsely accused of being notorious murderer "Ma Parker."
The real Kate Barker ("Ma" Barker) was killed in 1935.
Enjoy! (and it's an open thread)