I'm gonna leave this podcast series for you to listen to which I think can help: https://stuttertalk.com/category/what-i-wish-my-slp-knew-about-stuttering/  Not knowing or being nervous to talk about it is normal so you're in good company. But not talking about it because you don't want to draw attention to it or make them self conscious about it is the prevailing, but failing strategy. She already knows something is different. She's already seen a speech therapist before. She knows ignoring it isn't helping anything so and avoiding talking about it can be confusing and she may come up with unhelpful coping strategies.