Does my niece stutter ?

Does my niece stutter ? I don't know if this is the right sub So I have a niece who's 7 years old, sometimes especially when she excited or mad or emotional in general she struggles to the words out and stutter so much, but when she's relaxed she doesn't stutter as much She's been in so much last year I thought she might be dyslexic or something but she's good in school Is there a test or a way to make sure and will this go away on it's own