Hey, remember the dream Logan had on page 2 of chapter 12?
If you don't remember, you might want to re-read it.

Betsy Bobbin was originally created by Baum to replace Dorothy in his third stage musical, The Tik-Tok Man of Oz, because she was contractually tied solely to the 1903 Wizard of Oz broadway musical.

Betsy later showed up in the 8th Oz book, Tik-Tok of Oz, which was a loose adaptation of The Tik-Tok Man of Oz, which was, in turn, a loose adaptation of the 3rd Oz book, Ozma of Oz. So, Betsy Bobbin and Dorothy Gale canonically exist in the same universe as friends.

John R. Neill drew both girls with blonde bob cuts, which causes people to sometimes mistake illustrations of Betsy Bobbin as drawings of Dorothy. I've given Betsy a Judy Garland-inspired hair style and a height difference to differentiate them more.

The character designs for Betsy's idea of the Friends of Dorothy come from the 1933 Wizard of Oz cartoon, which predates the MGM movie!

You can watch it on YouTube here: