K.C.
My daughter lisped when she was little, too. I think it's pretty typical. "I made a thnowman! I want a thnack! Dat baby is thucking her fumb!" "How old are you?" "I'm FREE years old!" We practiced saying "shnowman" instead of "thnowman" because the SH sound has the "S" sound hidden in it and it's an easier transition than TH to S. I also asked her to try saying "Zat baby is shucking her sumb", which came out as "THat baby is shucking her THumb", and "I'm SREE years old", which came out perfectly as "I'm THREE years old". It wasn't that she couldn't make the "TH" sound, she did it perfectly well when she tried the "S" or "Z" sound, so we kept practicing saying "S"s and "Z"s for the "TH" sounds and saying "SSSSHHHHHH" to get the mouth feeling of how "SSSSS" would be and it totally worked - she actually practiced her way out of the lisping! By the time she was 4, the lisp was gone and all pronunciation and enunciation was perfect.