I've a feeling I may have only half an answer here, but the lady is vaudeville singer and comedienne Stella Mayhew.
As for the rest of the puzzle, I'm afraid I probably don't know Otto well enough to make the personal connection with her. But she was a keen motorist, seen below in her Palmer-Singer, circa 1910.
In a contemporary article in
The New York Dramatic Mirror she is quoted as saying:
I think that automobiling is one of the finest recreations going, but like everything else it has its faults, and one of the greatest of these is the fact that the driver is liable to try to make the car do impossible stunts, as I once did when I nearly persuaded mine to climb a tree one dark night just outside the city limits.
Have you perhaps been involved in a similar "incident"?
