In her youth, she, Professor Hastings, and Principal Lamont were childhood friends with dreams. Her dream was to protect nature and Pokémon and with Hastings' development of the Capture Styler and Lamont's Ranger School, that dream was realized and the Ranger Union was established.
In the manga
In the Darkrai Mission Story: Pokémon Ranger Vatonage - the Comic manga
Erma in the manga
Erma was at the Ranger Union where she named Kate as a Top Ranger and gave her a Vatonage Styler.