Qwiz - who are they and why is the woman an ongoing mystery?

Quiz hint: the woman at the top had some interesting information. She's also had 70s flings with Bill Johnston and Jacques Parizeau, both of whom stand pretty much at opposite ends of the language issue spectrum.
Someone got it, it's Carole Devault, and William Johnson. He co-wrote her biography. In fact, he wrote the whole thing based on stuff she told him, I know because he told me. She was involved in the FLQ and eventually became an informant, getting $30 a week for two weekly meetings with her RCMP controler Julien Giguere, plus a $15,000 flat fee for her cooperation, nowadays de Vault lives a private existence. Johnson says he doesn't really know where she is but we're not entirely convinced.
Here's a little bit from it:

How could I betray my friends? This was a question tht I would often be asked later, after my role was made public. The fact is that I did not see what I did as a betrayal. Insofar as FLQ actions had serious consequences. I seriously wanted to counter the FLQ. And insofar as they were only playing a game suited to naive adolescents, I too, was playing a game.

No one went to jail on my account. The police were worried about another outbreak of terrorism on the scale of the Otctober Crisis. When lesser acts were committed, the police tried mostly to contain them rather than send Felquistes to prison. I was there in case a crisis blew up.