My daughter started stuttering at 2.5 and still stutters 2 years later but mainly when tired or excited. We’ve been doing speech and language with her without her even seeing a therapist because where I live they see the parent and then the parents carry it all out. As well as all the things you’re already doing, we do 5 minutes “special time” every day (obviously we play with her etc more but this is special 1:1 time without her sister, screens, radios and so on just for her - and 5 minutes is the minimum we do it’s usually more, however 5 minutes is recommended so it actually gets done) Basically it’s play that she leads completely. We do what we she wants and talk or don’t as much as she wants to. We don’t ask questions just comment on what we’re doing or what we’re thinking. If we do ask questions it’s 1 question for every 4 comments. It doesn’t sound like a lot but it has made a huge difference. We do it before bed and my husband and I alternate who does it. We’ve started doing it with her little sister as well purely because she wanted it, so while I do special time with one of them, my husband does it with the other. My eldest has no idea it’s for her stutter but she looks forward to it every day.