Although the Blackstone comic book was a work of fiction, pages from the comics where Blackstone and Rhoda showed how to do magic tricks were later reprinted in a nonfiction book by Walter Gibson, who had also been the writer of the comic book.
The blonde girl character from the comics was also depicted on a souvenir program along with a photo of the real Blackstone.
Here is a 1940 photo of him with one of his assistants, who appears similar to the Rhoda character of the comics.
This might be the girl who they were depicting in the comics, as it seems that character was based on an actual girl.
Blackstone Magik Enterprises: