The double Cannes gold-winner lost her six-year battle with breast cancer in a London hospice on Saturday having been flown home from France after her condition deteriorated.
This week, senior industry figures led tributes to Dempsey, renowned for her uncompromising style and original mind. Tim Delaney, her former boss, described her as "one of the best dialogue writers in advertising".
A graduate of the Watford College creative course, Dempsey began her career at the former Hobson Bates. There, her ad for Tuf boots, featuring builders modelling their footwear as if on a catwalk, picked up a gold Lion at Cannes.
She later switched to Collett Dickenson Pearce at the height of its creative flowering where she met her husband of 27 years, John Bacon, the former Ogilvy & Mather and FCB joint creative director.
After a spell at French Gold Abbott, she joined BBDO's creative department, then led by Delaney. "It all came naturally to her," Delaney said. "She was very funny but intelligent with it and could have been a fantastic sitcom writer."
Shunning the chance to work on screenplays for the director Alan Parker, she began a 20-year partnership with the late art director Phil Mason. Although freelance, they established a permanent residence at Saatchi & Saatchi.
Dempsey's funeral takes place this Friday at St Mary's Church, Holly Place, Hampstead, at 1.30pm. Anybody who knew her is welcome to attend.