Gilly received a certificate in Botanical Art and Illustration with Anne Marie Evans from the New York Botanical Garden. Gilly's work has been selected to appear in several international juried exhibitions throughout the United States which include the Hunt Institute of Botanical Documentation at the Carngie Mellon University in Pittsburgh, PA., the United States Botanic Gardens in Washington, D.C., and many others. She received the Georg Jensen Award during the Third Exhibit of the Horticultural Society of New York. Her teaching experience includes teaching a Botanical Watercolor Techniques Class for Otis College of Art and Design during 2002, and teaching classes on Botanical Art Techniques at the Virginia Robinson Gardens in Beverly Hills from 2004 to 2008. Since 2013, she has been teaching small groups at her home studio on Mt. Washington in Los Angeles. These home studio classes are especially beneficial for those who like individualized instruction. They serve as a good introduction to botanical art and the basic skills that are involved.
Gilly served as President of the Botanical Artists Guild of Southern California from 1999 to 2005.
In addition to the botanical art Gilly has enjoyed doing, she developed an art program for elementary age children. She directed and was the head teacher of this program for 16 years.