[3] Del Deo taught at the Tyler School of Art, Temple University, and assisted her mother with the activities of the National Conference of Hand Weavers.

In the 1960s, she joined artist Ross Moffett in successfully opposing development of the Province Lands on Cape Cod.

[3] She was president of the Provincetown Symphony Orchestra, founded the local chapter of the ACLU, and raised funds for civil rights and anti-nuclear causes.

[3][18] "She fought with every fiber of her being to preserve the beauty and character of her adopted hometown", noted a former town official in a eulogy at her funeral.

"[15] In 2018, the Pilgrim Monument and Provincetown Museum hosted an exhibit, "Creating a Difference: The Del Deo Family of Provincetown: Art and Activism on the Outer Cape", and a performance "Daughter of the Dunes: The Literary Life of Josephine Del Deo", featuring her works.