DD, who is MG, hit normal milestones of walking and talking at about 11-12 months.

DS walked at about 12 months, but didn't talk until almost 27 months. The teachers were worried enough that suggested early intervention. Fortunately our pediatrician (the same one that identified him at 6 weeks as one of the most alert kids he had ever seen) told us that it would be a waste of time, and instead said that when DS decided to finally speak, it would be in full sentences. And that is exactly what happened at 27 months. His delay surprised us because he was mentally ahead of DD in all other measures.