Re: Delayed walking and development question..
Agree with the PP. Sitting on their knees is an easier form of sitting and the fact that he's still unstable while sitting on his bottom indicates he has some core strength issues. EI can help significantly. He's definitely getting close to a point when he should be walking, but the lack of stable sitting is the biggest red flag. Some therapy now will help get him going faster down the right path which will be good for him long term.