[3][4] Valentine was born on January 7, 1959, in Austin, Texas, an only child who was raised by her single mother, an English expatriate.

[6] In 1975, on a subsequent family visit to London with her mother, she answered an ad in Melody Maker and joined the fledgling Girlschool.

The Textones released two singles, including an unreleased Tom Petty song, before Valentine left the band in 1980.

The second album featured Valentine's previous Textones song "Vacation" as the title track and first single, after re-working the arrangement with Go-Gos' guitarist Charlotte Caffey.

The band struggled with internal difficulties during the recording of Talk Show, and tried to stay together after the departure of rhythm guitarist Jane Wiedlin.

[6] Returning to her rock roots, she formed the World's Cutest Killers, a line up she thought would be successful, featuring former Girlschool guitarist Kelly Johnson, her old friend Jesse Sublett on bass, drummer (future A&R man) Craig Aaronson, and keyboardist Jebin Bruni.

The group attracted the attention of producer Mike Chapman and recorded demos, which were scrapped, and the band split up.

[citation needed] In 1992, Valentine began her longest collaboration and partnership with singer and bassist Dominique Davalos.

[13] In 2005, Valentine released a solo recording, Light Years, that she co-produced, wrote, arranged and performed the guitar and vocal tracks.

[15] In March 2014, at South by Southwest she was inducted into the Austin Music Hall of Fame by members of Blondie (Debbie Harry, Chris Stein, and Clem Burke).

[18] As a result, Valentine rejoined the band to perform their first show together as a quintet in six years at New York's Bowery Ballroom on January 31, 2018.

[21] The group however were forced to cancel other West Coast dates scheduled for early January 2022 due to a COVID-19 case involving someone with the tour.

[22] While working to complete her inter-disciplinary degree in English and Fine Arts, Valentine has also begun taking writing jobs and public speaking engagements.

She was the keynote speaker at The American Heart Association's Go Red For Women annual event,[23] and for the MEOW Conference, where she also presented a Valor Award to her early inspiration Suzi Quatro.

[24] In 2014, Rainbow Light Nutritional Systems presented Valentine as part of its Game Changers promotional campaign.

[26] Valentine recruited underground influential musicians and Seattle-based singers to front the band and was musical director.