Gilly has received the Watercolor Program Certificate from master botanical art instructor Anne Marie Evans, of the New York Botanical Gardens, New York, and the Chelsea Physic Garden, London.

Since 2000, Gilly's works has appeared in a number of juried international exhibitions throughout the United States, including Longwood Gardens, Kennett Square, Pennsylvania, the United States Botanic Gardens in Washington, D.C., the horticultural Society of New York, the Loveland Museum/Gallery in Colorado and the Filoli Estate and Gardens, Woodside, California.

In 2000, she received the Georg Jensen Award from the American Society of Botanical Artists for painting exhibited at the Horticultural Society of New York.

Gilly has taught Botanical Watercolor Techniques for Otis College of Art and Design in Los Angeles and at the Virginia Robinson Gardens in Beverly Hills, California. She enjoys giving private lessons at her home studio in Mt. Washington in Los Angeles.

Gilly is a member of the American Society of Botanical Artists and is immediate past president from 199-2005 of the Botanical Artists Guild of Southern California. Her work is included a a permanent part of the botanical art collection at the Hunt Institute of Botanical Documentation at the Carnegie Mellon University and in private collections around the United States.