hello, im 16 years old and have a moderate to severe stutter. one thing that helps is people ignoring my stuttering (in the right scenario ofcourse). for example, my mum pretends i dont have it when we're having a regular conversation. if i experiencing a block or stutter, she pretends like it never happened and we carry on like usual, it helps me feel normal. another thing that helped, is taking a deep breathe before speaking and just taking it slow. i tend to experience blocks at the start of sentences, so i do a little "mmm" before i start speaking. if i were to greet you, id say "mmmhello, how are you?" but id say the "mmm" quiet enough so you would barely hear it. last thing, ask her if she'd like you to finish her sentences for her when shes stuttering. ive personally found i especially like people doing it when its taken me 10 seconds to get even a slight sound out. make sure to ask her about this though as some stutterers hate it. i wish you and her the best with her stutter :)