Before Episode 1
After the invasion of Paris by the German forces, she contacted the Assassins through the resistance. She was helping by spying on the german who came to the bar she was singing in.
In 1941, she was interested in joining the Assassins, and was the next candidate in the Mentor's list. She started a relationship with Peter around the same year.
Peter, knowing she was tracked down by the Templars, gave her his family ring, hoping she would become an Assassin after the Templars that chased her would be killed.