Your post is several years old, but in case you are still looking for info, here is a bit:
Walter Ellwood Jones, jr. (b. 28 Dec 1903, Philadelphia, PA), son (and quite possibly only child) of Walter Ellwood Jones (b. 28 Jul 1875, Beltsville, MD) and Mary Faries (b. abt 1878, Smyrna, DE).
Also living and traveling with them at various times is Elwood Sr.'s niece: Helen Pickering Jones (b. 8 Oct 1896, Philadelphia, PA), daughter of William J Jones (b. abt 1870, Beltsville, MD)
Ellwood jr. married Katherine "Kay" Underhill (b. 1909, Montclair, New Jersey), the daughter of Arthur Underhill (b. 24 Dec 1874, NYC) and Helen Elizabeth Sands (b. 5 Jan 1871, Brooklyn, NY) and sister of Farnam Sands Underhill (b. 7 Aug 1912, Speonk (Long Island), Suffolk, NY; d. 19 Sep 1981, Jupiter, Palm Beach, FL).
I don't yet have specific info on Kay and Ellwood's marriage, but according to immigration records they wer living in New Haven in 1926. According to Cornell Alumni News (1935 v37#16), by the time of her father's death in 1934 they were living in Caldwell, NJ.
At some point, possibly the early 60s, Kay moved to Reno, NV where she remained until her passing around 1996. Whether she moved with Ellwood or solo as the result of divorce or widowhood is as yet TBD. She and Ellwood jr. had one son I am aware of.