Her mother was a member of a family orchestra that toured hotels, while her father was a caterer and trumpeter in the band.
[1] After graduation, Drennan worked at a sweetshop in Notting Hill, London, while trying to establish herself as an artist.
Realising that a career as a painter was difficult without financial support, she started to send cartoons to the print media.
[1] From 1982 to 1992, Drennan had a commission to produce a series of quarter-page cartoons to advertise Fortnum & Mason in the Royal Academy of Art's magazine.
These often featured Sir Joshua Reynolds, the academy's first president, in conversation with the department store's founders.