Since the box had no markings, she did research sending letters to different sites trying to find information about the characters. She did get an email back explaining that they were from a 1936 cartoon "I'm a Big Shot Now". The cartoon takes place in Birdsville and is about a bunch of tough guy birds who are chased by the police (who offer a reward of 500 Worms).
She sold them in two sets of four on eBay and was surprised when the bids topped over $400. for four small glasses.
It is believed this is the same glass she sold, the lot was split up further and the glasses were sold individually.