1. 1-3 Months: Around the end of the first month you will probably get your first smile! Your baby will also lift his head when lying on his tummy, respond to sound, and spend a lot time staring at faces. By the end of the second month you might notice that your baby is fascinated with his hands, vocalizes a bit (but mostly in gurgles and coos), you might even get a few squeals, and hold his head up for short periods. As silly as it sounds, talk to your baby a lot. Narrate your day and point out things along your walks. By the end of the third month your baby will start to develop a social smile, recognize your face and scent, hold his head steady, and visually track objects. Hold an interesting toy in front of him for a couple of minutes. He’ll let you know when he’s finished playing by looking away. Follow your baby’s cues to avoid over-stimulation. You can provide opportunities to help your baby work on lifting his head by putting him on his tummy on a soft mat for a few minutes at a time.
2. 4-6 Months: Babies suddenly seem so much older when they hit the four month marker. Now is the time that you will start to see consistent eating and sleeping patterns emerge. Pay close attention and start working on that sleep schedule. A well-slept baby learns faster and grows steadily! By the end of the fourth month, look for your baby to smile and laugh, coo when you talk to him (there are few things better than this…enjoy!), bear some weight on his legs, and possibly even start grasping for toys. By the end of the fifth month, you can expect your baby to play with his hands and feet, and start distinguishing between bold colors. By the end of the sixth month, you have a whole new baby on your hands! Watch your baby roll over in both directions, turn toward sounds and voices, start to imitate sounds (talking!), sit without support, stick toys in his mouth, pass toys, and start solid food! Again, do NOT worry if all of these things are not happening for your baby at once. Firstborns tend to be held more, so physical milestones might not come as quickly. Be sure to put your baby down on a play mat regularly and do tummy time, despite the tears. They need opportunities to work on muscle building, especially neck strength. And sit nearby when he first starts sitting up independently, they topple over easily at this stage. *Now is a good time to start the baby proofing. Make sure there is a place clear of clutter and objects that might fall so that your baby can sit, roll, and play. Six months is also a good time to introduce Baby Sign Language. It will help decrease frustration and increase verbal skills.
3. 7-9 Months: Your baby is really growing now! By the end of the seventh month your baby is sitting up, responding to his own name, beginning to understand emotions by voice tone (be careful), dragging (or raking) objects, and possibly starting to lunge into a crawl. You can help your baby in his quest to move by placing toys just out of reach and encouraging him to grab them. By the end of the eighth month you can expect your baby to say “mama” and “dada” to both parents (the babbling will really start now!), pass objects between hands, and probably crawl. Make sure you are allowing plenty of floor time for your baby to work on these new skills. A baby who is always in a stroller or carrier is a baby who isn’t moving much! By the end of the ninth month your baby will stand while holding onto something, combine syllables (keep talking!), understand object permanence (which means peek-a-boo is no longer scary), and possibly cruise along furniture. Have you baby-proofed yet? If your baby is crawling and cruising you need to make sure that your home is safe. **During this time you want to introduce water in sippy cups (I recommend trying them out first, those valves can be hard.)
4. 10-12 Months: By the end of the first year, you will look back and wonder how it all happened! By the end of the tenth month your baby will be using a pincer grasp, waving “bye-bye”, and crawling well (some even walk). Blocks, stacking cups, and noisy toys will all be a source of focus and amusement. Toys are often packaged according to developmental level. Buy the appropriate toys for your baby’s age. Buying toys that are above your baby’s developmental level will lead to frustration. Around eleven months you can expect your baby to cruise (walking while holding furniture) well, stand alone for a few seconds, say “mama” and “dada” to the correct parent, and play peek-a-boo. You can also expect some separation anxiety to start. If you are leaving your baby with a nanny, babysitter, or in daycare, establish a goodbye routine to make the separation easier. By the end of the twelfth month your baby will be imitating others, responding to simple requests, trying to scribble, walking (although many don’t walk until 15 months), repeating sounds and gestures for attention, finger feeding, and showing preferences. Reading regularly helps your baby connect objects to words and work on language development. Offer large crayons and paper and let your baby scribble away. Break out the toddler tunes and sing regularly, this also helps with language development.
5. Causes for concern: I repeat: All babies develop differently! Try to enjoy your baby and have fun with all of the stages. Before you know it, you will have a toddler on your hands! But, if you suspect that something is not right (and please rely on your parent intuition), check with your pediatrician. There is no harm in asking. Here are a few red flags: If your baby does not respond to loud sounds, does not smile at all, is not babbling at all by four months, does not reach or grasp for toys by four months, does not pay attention to (or seems frightened by) new faces, does not visually track objects by three months, or seems to have lost previously gained skills, call your pediatrician.
Tracking Developmental Milestones can be a lot of fun. It’s a great way to organize your baby book and preserve memories. Just remember to avoid comparing your baby to others. They all develop at their own pace and, chances are, your baby is doing just fine!
She even met a little boy she followed around...he ended up giving her a hug... 
