Bobbi Morse, Mockingbird
First appearance: Astonishing Tales #6, June 1971
Current status: dead
Was subjected to the following act of discrimination: at the end of West Coast Avengers in 1993, where she’d been a longtime member, she was shot in the back and murdered by Mephisto. Hawkeye/Clint Barton, her husband for several years, became a widower.
What’s wrong with how this was done? Yet another pointless offing of a female character, and what really made it bombastic was that, as far as I know, Mephisto had never been interested in actually killing anyone before. Put another way, it wasn't like him to try and take anyone's life for real.
Since then, there’s been one story in which she turned up as a corpse in a plot conceived by the Grim Reaper to destroy the Avengers. Yet, she remains dead, with no clear way to tell if she’ll ever be revived to full life again or not.