JSA (or All-Star Squadron) heroine Liberty Belle, in the DCU. Don't have a picture handy. I think she's the mom of Jesse Quick? (Her father was Jonny Quick, I think)
1940s female avengers include the Black Cat, created by Simon and Kubert, the Phantom Lady, created by Arthur Peedy and Lady Luck, created by Will Eisner and Klaus Nordling. Try entering 'female masked avenger' or a variant into Google.
Oh, on the "why," Ma Hunkel is a superior hero because she is FORMIDABLE, and formidable in a very feminine way. She's a matriarch. She takes no guff. This makes her kind of unique in comics... usually the mother figures are based around ideas of nurturing rather than disciplining. Ma Hunkel knocked the baddies into shape.
