Praise be to Allah.
There is nothing wrong with this woman leading her sisters in praying taraweeh in congregation, or leading them in prayer, so long as she adheres to the conditions, pillars (essential parts) and obligatory parts of the prayer. Perhaps leading others will help her to control herself and not pay any attention to the waswaas.
It is expected that the doubts will become less and she will become more in control of her prayer when there are others praying behind her.
And Allaah knows best.