@tierra618, I've never used cheats to raise my toddler's skills, but I do know that many cheats require the "testingcheats on" cheat to work, so enter that cheat and then the cheat you already tried using (if you haven't yet.) 😉
I tried to look for specific toddler cheats from Carl's Sims 4 Guide, and the only ones I saw were the cheats that have to do with the Parenthood GP. I don't know if you have that Game Pack or not, but these cheats are to get a specific Character trait that you would normally earn in the game, such as Conflict Resolution, Responsibility, etc. Here is the link: https://www.carls-sims-4-guide.com/cheats.php Scroll down to the Parenthood section. 🙂
Best of luck! 😉