There is an excellent support group on Facebook for parents of children who stammer which you can ask to join if you think it might be helpful:
Here’s a link to support from the charity Stamma, including parent groups:
Please follow this link to the Michael Palin Centre which gives lots of information about stammering including top tips for communicating with a young child with a stammer:
Here are some websites which have activities and resources to help children to regulate their emotions and build their confidence.
This video is a great one to watch together with children:
Sam’s poem, I have a stammer. https://www.youtube.com/watch?v=9aWSkk0UTH0
Why do some children stammer?
This is a lovely video of a therapist explaining about how to keep things balanced to maximise smooth speech. why do some children stammer - YouTube
Understanding stammering in more detail
This is a great video to help you identify factors which may be contributing to or maintaining your child’s stammer. Understanding Stammering in More Detail - YouTube
The Communication Chain
Steph Burgess specialist speech and language therapist provides a good insight into how your child’s language development may relate to stammering. https://www.youtube.com/watch?v=8YsI2VXSwX8&t=19s