Hey there! /o/ I am so, so sorry about the terrible delay. asdfghkjl; I’ll just get right into things!
Okay, for babies. Generally, pretty much all they do is eat, sleep, poop, and cry. Hahaha. Seriously!!! Of course, all babies have their differences — some cry a lot, some don’t cry at all, some sleep a lot, some are more energetic — but those are their base functions.
As with all characters (and this goes for toddlers and five to six year olds as well), when describing babies, make sure to incorporate the five senses. (Well, maybe not taste. That’d be a little concerning…) Touch, smell, sight, sound!
Babies in general are very soft, very warm, and to most, very cute. Depending on how far along the baby is, they may be very light in your arms or rather solid (especially if they’re nearing their first birthday). Ordinarily, their skin is very smooth, very delicate. Everything about them is pretty tiny — hands, feet, nose, ears, torso — except their heads and eyes! S’part of what makes them cute (or as I read somewhere).
Most have a distinct smell — hopefully clean! — of maybe baby powder or milk or baby formula.
“If you look at baby products from Spain or France, they tend to have orange blossom as an ingredient, because that’s in the countryside and that’s fresh,” said Michelle Krell Kydd, a fragrance industry consultant and prominent flavor and fragrance blogger. “Americans,” on the other hand, “have a love affair with vanilla and powdery scents.” (x)
At this point, they’re all about observing everything, grabbing at things, touching and babbling.
Again, all babies are different and reach certain stages at different times, but my godkid’s almost at her first birthday, and she’s able to say “Hi!” and “I want that!” (typical American, hahaha~). She’s very observant, and she knows to look you in the eye and to look back at you if she wants something (as well as to reach for it). At this point, she can’t walk on her own, but she’s crawling, and is able to wobble on her feet with help.
Now, as for toddlers! Toddlers at ages two to four are developing “the language skills that help them express their ideas, wants, and needs” (x). They don’t have much concept of self-control or logic, so tantrums and the like are very likely. They’re also beginning to make their own choices and are exploring the world that’s theirs, and that’s probably a big reason as to why there’s such sayings as a child being in their “terrible twos” or “fearsome fours”.
Again, use the senses to describe your toddler character. They’ve grown a little and are walking — depending on the age — and they’re starting to grow into their limbs. They’re probably gonna have a lot of energy to expend to go along with being inquisitive. Chatter is gonna be a thing as they expand their vocabulary.
Moving on to older kids. Kids at the five- to six-year-old age are just learning how to read or at least are beginning to grasp literacy. And they are definitely talking by now.
"Sentence structures may now incorporate five or more words, and vocabulary is between 1,000 and 2,000 words. Speech at this age should be completely intelligible, although there may be some developmental sound errors and stuttering, particularly among boys.
"Preschoolers generally are able to make comments and requests and give directions. They should know the names and gender of family members and other personal information. They often play with words and make up silly words and stories." (x)
They’re inquisitive and they ask a lot of questions. They may still throw the occasional tantrum (depending on their personalities) but generally, they have a good concept of rules. Most are in kindergarten or first grade, so they’re developing a lot of things, like social skills! They may also be at an age where they’re able to help out with little things like putting the cereal away and such~
Other tips! If you know anyone — a relative, a friend — who has or knows a baby, a toddler, or a young kid of five or six, you should definitely tap that source! Perhaps if you live near a playground or know of a playground within walking/driving distance, check it out! People watching is a valuable resource for writers, and nothing beats real life experience.
If you don’t have any of these sources, things like parenting sites or baby/kid books are good resources as well!
And lastly, here are some other sources that you can check for help with your dilemma!
Hope this helped! And again, so sorry about how long it took to get to you. OTL
P.S. For all the parents/babysitters/kids with siblings out there! Anyone have anything to chip in?