Sapp was born in London and was educated at Benenden School, Kent and then the English School of Languages, Chaeau d’Oex, Switzerland. After this she studied at Epsom School of Art, attending her husband Reg Sapp’s portrait class for seven years. Prue Sapp was a member of the Chelsea Art Society.

She exhibited widely at The New English Art Club, The Royal Society of Art Painters, The Hyde Park Galleries as well as The Royal Academy.