Pre-school Milestone Skills such as taking a first step, smiling for the first time, and waving “bye bye” are called developmental milestones. Children reach milestones in how they play, learn, speak, act, and move (crawling, walking, etc.). Your Baby at 2 Months 418 KB Your Baby at 4 Months 421 KB Your Baby at 6 Months 424 KB Your Baby at 9 Months 422 KB Your Child at 1 Year 424 KB Your Child at 18 Months 429 KB Your Child at 2 Years 425 KB Your Child at 3 Years 427 KB