Here's a well dressed model working a stand at the 1939 Chicago Auto Show. I have some questions. The machine she is demonstrating looks to be possibly a disc sander on a pivot, is she grinding those (asbestos) brake shoes?
The discs all over the backdrop read Brakes Certified, which doesn't seem to make sense, was the company named Certified Brakes? Nothing definitive comes up on Google.
Btw, we have no evidence this is David Aldana's mother.