Ds is 4yo and a great talker. :) but he is missing some sounds. We are waiting on a SLT appointment but they are massively understaffed here so who know when that'll happen. 
Do anyone have any suggestions for the /s/ sound?
Ds has a frontal lisp ATM so yes becomes ye-th. I have done a lot of googling but am struggling to help him make the sound himself.
Any ideas! :)