Mary Louisa Price deMoll (1871-1902) Will’s youngest sister, studied painting at the Pennsylvania Museum School of Industrial Art. She had an interest in painting flowers. She was an avid gardener, and was put in charge of beautifying the landscape when the group first moved to Rose Valley. She died during the birth of her only child, Carl deMoll Jr. in 1902. The walnut trees on Old Mill Lane and the sycamore trees at the door of Hedgerow Theatre were planted as a memorial to her.

Source: Exhibition of Rose Valley Art and Handicrafts 2001
History of Rose Valley, vol.1