Sims 4 child poisoned

@mattheamallow  oh my goodness, I couldn't ignore that headline!

Could you explain a bit more about the incident? What kind of poison was it?

In these situations where it looks like a Sim may be lost I exit without saving to go back to the point before it happened, or I revert to my backup copy. With some things, like jungle curses depending on what they are and their severity I've used Moodlet Solvers too with varying degrees of success. You can share Moodlet Solvers too, so if the parent has 500 reward points they can buy one and place it next to the child to drink. Are you talking about the Antidote purchased on the computer, I haven't tried that for a child. I'd always assumed if you put the antidote down any Sim could pick it up and drink it. I add them to my camping stores for Sims to just take for free if they are poisoned.

I don't know how severe it is but if the child can't be saved, if your Sim has a high gardening skill you can purchase some rare seed packets to find a death flower for another Sim to give to the Reaper when he arrives, if you've been shown a countdown clock to their imminent demise. Or you can keep the child as a ghost and create Ambrosia to revive them. I've done that before and it took me a couple of Sim weeks but it worked (Although it's a gloomy process). Sometimes if the Reaper arrives you can also plead with him and he sometimes spares the Sim.