There is an option in the mod to phantasy speed grow them to productive age (author has said that it will be 1 day = 1 year). If you do not use this option, I am told that they will lie in bed for 16 years. I have not used this option yet, so I don't know for sure.
I am using Children and Pregnancy mod for the life-stage part (for this, be sure to turn off pregnancy in the CnP, turn on life stage for your respective races, turn off phantasy growth(?) in SJW). You need to adjust the speed factor depending on your pawn race, but you can still speed the growth and even enjoy the baby/toddler/child stages. You can get them to start working when they get to a child (though slower in work).
The Children and Pregnancy mod, however, has been set as deprecated by the authors and no longer being updated in steam, so use at your own risk.

The one we had lied in bed for 1.3 years, after what he walked and eat (and joked with other) like a big boy, though slowly --and that's all he could do before a drop pod raid decapitated little fella.

well it is how it goes age 1 is baby stage only sleep and incapacitated really, then you get to infant stage where he start to roam about, then after age 6 they will work on basic work hauling cleaning then more complicated work option open as they age, recommended using school and learning so you can farm them for intellectual skill, they also will learn to do job better, so all in all about 8 years before they are capable doing decent work, be careful they are squishy they would die from couple fist blow recommended building bunker area where they can safely hide during raid or else the death toll could make your colonist go insane.

also they doesn't eat much food they only eat less and less the younger they are so making special tab for food is recommended, feeding them stew is overfed they should be fed lighter food, DO NOT allow them to use drugs single flake could hammer them, smoking smokeleaf could make them pass out, drinking beer and they are drunk and basically move very slow and useless.

recommended using modded recreation food to feed them like candy, sushi, milk choco, juice or that kind of stuff, steak, stew, stirfry is no go.

The last time I tried to play through childhood stages my toddlers started acting out because of lack of entertainment, they can't operate the TV, so if it's on and someone is watching great, but when they leave and switch the TV off they can't watch anymore. Constant lack of entertainment and some unwise zoning and I had an alcoholic toddler who needed a transplant. The other one wandered outside in winter and got eaten by a hungry predator. Then there is the hefty negative penalties to having a child die, and it effects everyone, the parents most of all. I haven't bothered with childhood since then, use the Phantasy option.

There is a mod to add aging capsules but it's fairly far up the research tree and takes a lot of power.