I am going to try and potty train DD1,3, who has CP and gobal developmental delays over the summer but would also like to train DD2, 21 months, is she too young, she understands the concept of the potty and can say wee and poo, but i am worried that she is too young. I want both of them dry and know doing it together is a good idea as they will learn of each other but.........I don't know.........mmmmmmmm