L.G.
Potty training takes time. I know my first son was speech delayed and he learn at aroung three and half. He went to public school at the time and he was in a program called PPCD you might to check with your school district. It was very helpful having support from others. Right now I'm trying very hard with my three old girl she is very bright but she just would potty train and I'm at my wits ends. I also have a 2 year old but she's not ready either. I am tempted to try to teach them together but when I think about it I feel like I can't do it. My youngest girl is also very small for her age she is 25 months and she only wieghts about 21 pounds. I'm afraid she would fall in. I never used the potty chair. I have anyways used the seat that over the toliet chair, it's more convient and clean IMO.
Good luck
Leti