Sims/Pets age up multiple times in a row

That sounds really frustrating, especially when you're trying to do the 100 Baby Challenge! The 'double aging' glitch must be making it nearly impossible to progress. Since you’re playing without mods or custom content, it does seem like this might be a game issue rather than something on your end. Here are a few things you can try:

1. Check the Age Settings: Make sure your game settings haven’t been accidentally changed. Go to the game options and verify that your lifespan settings are as you want them.
2. Repair the Game: Through the EA app (or Origin if you’re using that), you can try repairing the game files. Right-click on the Sims 4 in your library and select 'Repair.' This might fix any corrupted files causing the aging issue.
3. Reset the Sim: If the problem persists with a specific Sim, try resetting them. You can do this by opening the cheat console (Ctrl + Shift + C), typing resetSim [Sim's full name], and pressing Enter.
4. Check for Updates: Sometimes, these kinds of issues get fixed in patches, so make sure your game is up to date.
5. Contact Support: If the problem continues, it might be worth reaching out to EA Support. They might be able to help, especially if it's a less common bug.

I hope one of these steps helps, and you can get back to your challenge without any more aging issues!

I also had this issue. I let infant age up and it skipped toddler phase.

Three times this has happend to me since I downloaded Lovestruck; if the smallest toddler doesn´t get help to age up (by birthday cake), but has to grow up automaticly, they age up twice in a row! They go from the smallest toddler directly to school child, skipping  the toddler age where you can pottie train them.