Hi, I didn't find any family members in a 1930 Census.
Since you know where and when each member died, I'd look for their obituaries. You may request the obituaries for Nevada County at Nevada County Genealogical Society, rootsweb.ancestry.com/~cancgs/research_policy.htm .
If that doesn't work out, try Random Acts Genealogical Kindness. Go to raogk.org, read guidelines, choose California, and choose ALL for County.
The obituary for Lorna might be in Alameda Co. You can use RAOGK for that County or contact the Alameda County Library, aclibrary.org/.
After you receive the obituaries, you also might want copies of their marriage and death certificates. You can contact the Nevada County Clerk-Recorder's office (new.mynevadacounty.com/)for these copies.
For Lorna's death certificate, do a Google search for Alameda County Clerk-Recorder . Successful Searching!