For more than a decade, Marshall has been conducting studio art classes in mosaic and shell design applications, as well as the visual arts. She frequently lectures at museums, art schools and private clubs along the East Coast. She also designs and consults with communities on outdoor mosaic projects for public walkways and parks. Marshall has appeared on both the Home and Garden and DIY networks. Her work has been exhibited and sold in galleries and museum shops throughout North America. She lives in Hudson, N.Y.