The Sims 4 gives your Sims the gift of children, but it also burdens them (and you by extension) with caring for these sensitive young Sims. Childcare is an option, but not entirely.
A nanny definitely helps, but they eventually clock out and hand your kids back to you. How do you get them to stay, with or without mods?
How do you hire a live-in Nanny for children in The Sims 4?
Technically, you can't have a Live-In Nanny for your Sims without using mods in The Sims 4. There are a couple of workarounds that technically work, though. Both lack the complete experience players desire and may not function as you'd imagine. Still, these options are solid for those players who are determined not use mods (also called vanilla players).
How to hire a Butler
As long as you own the Vintage Glamour stuff pack, you can use your Sim's smartphone to hire a Butler to live on your lot and care for your children. Ensure you have a bedroom built especially for the Butler before hiring the service, or the Butler will fail to materialize.
Butlers will instinctively focus on housework with some light childcare, if you don't instruct them otherwise. Simply clicking on the Butler, though, will allow you to tell them to only care for kids. Don't leave them to their devices entirely, as Butlers sometimes act buggy and ignore your requests.
How to trap a Nanny
If you don't want a Butler and instead want an actual Nanny, you can attempt to hire a Nanny and then lock them in your home. You do this by waiting until they enter the house, then clicking on all doors that lead outside. Then, choose the option to lock for all Sims that aren't in the household. Be warned that this doesn't always work, and sometimes the Nanny just disappears from the lot.
Some Simmers have reported better odds of this method succeeding when enabling Free Services trait earned through the Rewards Store. Others noted that adding the nanny as a roommate can work especially well (though this method did not work for me).
How to use mods for a live-in Nanny in The Sims 4
For those hoping to nab a fully capable Live-In Nanny in The Sims 4, using LittleMsSam's Maid & Gardener Service mod is where you'd want to do. Download the mod and unzip the folder's contents before moving those files over to the Mods folder (all of this on your own PC files, not in-game).
Start up The Sims 4 and head over to your Sim's smartphone. Hit the Hire a Live-In Service option and then choose to Hire a Live-In Nanny. Be certain that you have a bed for the Nanny Sim use, and also be sure it is properly assigned to them, just like you would with a Butler.
How to hire other live-in workers in The Sims 4
How to hire a live-in Maid & Gardener with mods
Looking to also grab yourself help in the form of a live-in maid and/or gardener? Then you can also use the LittleMsSam's Maid & Gardener Service mod, which was intended for exactly this purpose. Just download this mod, boot up your game, and go to your Sim's cellphone. Choose the new option that says Hire a Live-In Service, and select your helper of choice. Then, you're all set!
Want to learn more about The Sims 4? If so, check out How to Make Objects Bigger and Smaller – The Sims 4 Resize Guide on Pro Game Guides.