Following a career in fashion and textile design, Ainslie gained a Diploma in Botanical Illustration at the English Gardening School in 1995. Ainslie was a founder member of the Chelsea Physic Garden Florilegium Society, nineteen of her illustrations in watercolour or pen and ink are in the Society's archives, and with other members she received an RHS gold medal for a joint exhibit in 1999. She exhibited widely for a number of years, and her paintings are held in public and private collections in Europe and the United States.