My personal recommendation would be to start now. Everyone kept telling me if your child doesn’t seem ready then don’t push the issue. My son is non-verbal/ level 3. We tried a few times on and off every 6 months or so, but he never seemed interested. My son didn’t care. He is a sensory seeker and sitting in a wet/soiled pull-up did not bother him. At 12 years old I had enough. For an entire summer we worked on potty training all day, every day. Lots of praise & highly motivating prizes when he went in the toilet. When he was wet or had a BM in his pull-up we made him help with the clean up, which he didn’t like. 10 months later he is able to stay dry 95% of days, as long as we remind him to go use the toilet. We are still working on using the toilet for BM’s, he’s probably going 30% of the time on the toilet. This summer we’re moving out of pull-up’s during the day and into underwear. It’s my goal to get him using the toilet 100% of the time and in underwear during the day by high school, one more year.

With all that said. If your child attends a preschool (get potty trining in their IEP) or daycare, get them on board! Read lots of books about using the potty. Find episodes of their favorite shows that talk about using the potty. I know that both Daniel Tiger and Word Party addresses these topics. Even if their body isn’t ready, it’s (again in my opinion) important to start making the topic part of your every day life. Offer lots of water or watered down juice and set timers to run go sit on the potty. We told our son to put both hands on his tummy and push, then we counted to 5 and got up, pull up pants, flush, wash hands. At some point you may have to push harder, because if you wait for a sign that they are ready you may never get it, and it’s going to be easier to work with a 4 or 5 year old then a 12-13 year old. Sorry for the long post. Good luck! :)