Nancy Lilian Heath (known as Nan) was born in north Staffordshire. At Brownhills High School in the Potteries she excelled at art and music. In 1943 she gained her teaching qualifications from Hereford Teacher Training College. Thereafter she taught for 28 years in Wolstanton, living at home with her mother in Hanley, Stoke-on-Trent. The school choirs which she trained won awards on two occasions. In 1952 she took a year out from teaching to study at the Bath Academy of Art, which helped her to develop her own particular artistic style.

In the late 1960s Nan first visited the Isles of Scilly on a painting holiday. Returning in 1971, while staying at a guest house on St Mary's, she fell in love with Frank Smith. The couple were married later that year and Nan moved to St Mary's soon after. She continued to paint under her maiden name. Nan's flower-filled watercolour landscapes and seascapes proved so popular that prints of them were produced, to fulfil the demand. In 1989 Frank and Nan opened Nan Heath Studio Four close to their home.

Solo exhibitions of Nan's work were held in the Potteries in 1975 and 1977. Several shows were held over the years at the Isles of Scilly Museum. In 1992, two of her original watercolours were accepted for the annual Royal Academy of Art Exhibition at the Mall Galleries in London.

Nan's death at the age of 72 was received with widespread shock and sorrow. Her widower Frank Smith died in 2009.