Lisp in 3 YO?

Give it a little more time and correct her when you hear the lisp. Then make her say the word correctly. Practice the /s/ phoneme with her by calling it her 'snake' sound. You can also add tactile cues and rub your finger up and down her arm while saying /s/.

Make sure she is keeping her tongue behind her teeth (in it's cage). That's basically what a lisp is, the tongue coming forward, outside the teeth.

If she was saying it correctly then she can do it again. Did she start preschool or a new program where she is around other kids? If a peer is talking like that she could be mimicing it.

Yes, they can develop a lisp. The best thing you can do is ask for help from a speech therapist to work the lisp out.

Ask for a speech evaluation.

Dawn

The speech things come and go in little kids. Eventually they sort it all out and everything is fine. My grandkids all said gwam instead of gram for a while. And trouble with the letter L lead to things being yiked instead of liked. Tr's were f's for a time for train was fain and truck was well embarassing. But as they grew up and matured all the letters began to come together and it's not a problem.

Hang in there and just make sure you say everything right. She'll catch on. Don't make a huge deal out of it.

Im sure shes fine. little kids love to lisp. :)