I don't know if Amy Winehouse would have considered herself a feminist icon (and I'm not sure I even consider her one), but there is no doubt that she was a very talented lady who inspired and influenced many other female singers and songwriters.
Amy's music was influenced by jazz, soul, R&B and girl groups from the 60's. Her frank, sometimes rude, lyrics were partly inspired by the raw grittiness of 1990's female hip-hop artists, such as Salt 'n' Peppa. The old-fashioned R&B sound paired with hip-hop influenced vocals gave her songs a contemporary feel that is unparalleled among other modern R&B singers like Joss Stone or Duffy. Additionally, her lyrics were wise beyond her years; Love is a Losing Game was written when she was in her early twenties, but it sounds like it was written by someone who had lived a long life.
Amy never worried about social approval or let it hold her back. She wrote about her experiences with addiction, love and breakups with brutal honesty. She was never a polished, manufactured performer; her music was specific to her experiences and she wasn't afraid to write songs that were deep, dark and troubling. Many female musicians feel they need to "tone it down" to be commercially successful, but Amy refused to tone it down.
Below is a great video featuring a younger, healthier Amy Winehouse singing Stronger Than Me and playing the guitar. This is how she should be remembered... as a beautiful, talented singer and songwriter. Rest in peace Amy, and thank you for all the wonderful music you made.