This patient support community is for discussions relating to the challenges of parenting
toddlers (age 1-5), including physical, speech, sensory, cognitive and emotional development, choosing a daycare/nanny, games & activities, and toilet training.
I doubt very much if the "brother scaring her" had much to do with the stuttering, but it would help if he stopped this behaviour. After all, she is just a little girl. Unless you see additional signs of anxiety, there would be no reason to see a professional; stuttering at this age is not uncommon. If it would make you feel better, then mention it to your family doctor on your next visit. I wish you the best ...