A.D.
Hi P. - I know you've gotten a lot of advice but just thought I'd chime in! My son is the same age - the rule of thumb that I have heard is to start Stage 2 when they can sit independently (my son is just starting to do this at 7 mos) and then to start stage 3 when they begin to crawl. Basically, if they can do those things, then they are developmentally ready to move to the next stage of food. Best of luck!!