Hi Robert, I don't think you'll find descendants just by posting this message. I think you'll have to "hunt them down".
An Elvessa Mitchell was born 1 Dec 1916, Los Angeles Co. Mother's Maiden Name=Gerst. Source: California Birth Index 1905-95, Ancestry.
I didn't find the family in any census until the 1930 Oakland, Alameda Co. Census. Joseph H. Mitchell, b. MO, 52, marr @ 37, real estate agent. Freda, wife, b. CA, 45, marr @ 30. Elvessa, dau, b. CA, 13.
Since Elvessa was born in 1916 in Los Angeles Co., I think Joseph and Freda were married there about 1915.
I didn't find Joseph or Freda's death info in California. You might want to find a death look-up volunteer at Randam Acts Genealogical Kindness. Go to raogk.org, read guidelines, choose California, choose Alameda and choose a volunteer who does public record lookups.
After you find their death dates, then you can request copies of their obituaries and find more info about the other two daughters.
An Elvessa Lynn Osgood b. 1 Dec 1916, CA died 26 Sept. 1994, Alameda Co. Mother's Maiden Name-Gerst. Father's Surname=Mitchell. Source: California Death Index 1940-97, Ancestry.
Now use RAOGK to find a volunteer who will copy her obituary.
After you've received her obituary, use 411people.com, zabasearch.com or whitepages.com to find current contact info for her survivors. Successful Searching!