This is the placeholder for first year
When your child is lying on her back and you pull her with her hands, her head will fall back because she still does not have neck support. She should be able to fix at a face, follow an object with her eyes through a range of 90 degrees and startle to sudden noise. She should smile convincingly and should be crying and cooing.
He should have appropriate neck support. If he lies on his tummy, he should be able to raise his head and upper trunk. By now his hands are not always forming a fist and by 4 months, he should stop fisting. For a fleeting period during this time, he will discover he has hands and will look at them before using them (hand regard). He should now be playing with his hands and bringing them to the midline. He will hold a rattle placed on his hands. He can follow an object with his eyes through a range of 180 degrees. He now laughs and squeals and is aware that smile attracts attention. He makes noises on social contact and turns to sounds at the same level.
At this age, she should be trying to sit without support, albeit unsteadily. She is likely to be rolling, first from front to back and slightly later, from back to front. You should be able to demonstrate the downward parachute reflex with her; holding her on her sides, when you bring her down suddenly, she will raise her hands as if to clutch at something. She can now hold onto slender objects and shake rattles. She has a tendency to mouth objects she gets her hands on. She plays with her feet and holds her bottle when being fed. She produces unintelligible babble, says vowels and syllables and turns when her name is called. She is not shy!
He should now be able to sit steadily and will right himself when you try and push him on the sides. He can stand holding onto something if placed appropriately. He now exhibits forward parachute reflex; if you place him frontal body down, his hands reach out automatically for the approaching surface. He reaches out for small objects like raisins using a crude pincer grasp. He points with his index finger and understands "no" and "bye bye". His first word is "dada" to the mother's chagrin but this is because it is an easy word to say, he will start saying "mama" shortly after. He will have a 2 syllable babble.