Leon is actually not her real name. Her dream was to be the best tailor, but when she achieved that dream she still felt unsatisfied. She assumed a new identity and came to Kirchen Bell.
Although she doesn't appear in Atelier Firis, the clothes that made she win the contest in Adalett can be bought by Firis for 20,000 coins at Nanna's shop in Reisenberg.
In Atelier Lydie & Suelle, Fritz purchases a set of her clothes for his wife. Pamela mentions she has many students.