I found this death notice for Mary
PITTSBURGH POST GAZETTE FEBRUARY 2, 1940
Aiken-On Thursday, February 1, 1940 at 5:30 A.M., Mary Ann Aiken, age 83 years, at her home in Bakertown, PA., mother of Frank M. of Valencia, PA, Roy C. of Bakerstown, and Mrs. Helen White of California. Funeral services on Feb. 3 from the Bakerstown Presbyterian Church at 2 o'clock. Friends invited.
The way I found it was to first go to the Pennsylvania board of health site to find her exact date of death. You need the soundex code, which for Aiken in 250.
Then I went to the www.linkpendium.com
site - it has pages for every state and county. I found some Pittsburgh papers there on Google that you can browse.
Next, I went to the California death index to look for Helen White and I found this
Helen Hadassh White born 10/14/1893
Fathers name AIKEN born PENNSYLVANIA died in KERN county 01/29/1983
Unfortunately, it doesn't list her Mom's maiden name