Nah.
The whole fake Indian ploy was so disgusting that there is no reason to ever feel guilty about beating both Lieawatha herself and all of her followers over the head with it again.
When is the right time to bring that up?
It is always the right time to bring that up.
When is enough enough?
When she has taken a vow of poverty, entered a convent, and toiled away quietly for forty years in obscurity to make restitution. I would say that is an adequate prerequisite.
Yes, she blew it with that. Not to be “cool,” but to get a huge get ahead.
Apologize and take responsibility for de-frauding the minority spoils system to get ahead in life.