Console commands are too much effort.
Fortunately for us, there's a mod.
The Killable Children
mod: Allows the children of Skyrim to die.
Affects the Breton, Imperial, Nord and Redguard children.
You can download it from Nexus Mods here .
(Note that Nexus Mods requires you to sign up for a free account for age verification purposes, I believe.)
gaming.stackexchange.com/users/3129/LessPop_MoreFizz
Open the console ( ` by default).
Type in help
<kidsNameGoesHere> 4 .
You'll see a list of ID's, one of them will say something like: _NPC (somenumberswillbehere)
kid'sname
Next type in SetEssential <thenumbersfrombefore> 0 at the console and hit ↲ Enter .
Replace with the kid's npcID, and he should be killable, unless Bethesda implemented their invulnerability in a unique way.
gaming.stackexchange.com/users/6914/Arkive
The mods, Killable children V2 and Killable and Lootable Children allow killing of children, but at the same time, setting as unkillable or 'essential', certain quest-related children, preventing bugs and avoiding missing some quests, which is like the vanilla Skyrim behavior where certain quest-related NPCs can not be killed.
The Killable and Lootable Children
mod also allows you to loot children, and makes the 'essential' children, 'non-essential' when their related quests are finished.
gaming.stackexchange.com/users/4797/galacticninja
Just click on the person or child while your console is open ( ~ ) then type SetEssential 0 .
Don't type npcid manually or you'll get errors most of the time.
I have noticed that a lot of npcids are different between the 360 and PC version while some are still the same, so just click to target then type command without the need for the npcid specification.
gaming.stackexchange.com/users/18759/Anonymous
You can kill children in the PC version of skyrim by changing their races in the setrace commend.
once you change them you can be able to kill them with the kill command to not get a bounty.
this works if you want to kidnap a child WITHOUT teleporting.
or you can download a mod that doesnt require doing this process.
gaming.stackexchange.com/users/49343/Anonymous A
If you've been playing a decent amount of Skyrim, you may have noticed that children are annoying.  Really  annoying. However, while trying to bash one of the little snots into the ground to teach him some manners, I noticed that they're invulnerable to damage.  Obviously, they're witches, or at the very least cheaters. Is there a console command to make them less invincible? If not, is there one that will shut them up?
How do you kill children?
gaming.stackexchange.com
<the-elder-scrolls-5-skyrim>
gaming.stackexchange.com/questions/37257
gaming.stackexchange.com/users/1649/Artless
Certain children that are essential to the quest are not killable. Evidently through some mods or console commands children could be killed.
There could be a solution via certain mods. It is suggested that console commands could solve this problem.