Re: Bought Sims 3 Expansion through EA app, not showing up in game/option to select

@d_connor14  Please clear the EA App's cache and restart your computer.

https://help.ea.com/en-us/help/faq/clear-cache-to-fix-problems-with-your-games/

If that doesn't help, you may need to uninstall and reinstall Sims 3 entirely.  I'd actually suggest making a backup copy of the game's program files, or at least the packs' folders inside the main Sims 3 folder, just in case you run into this issue:

https://answers.ea.com/t5/Technical-Issues-PC/Sims-3-DLC-stuck-on-preparing/m-p/12372752#M256864

The idea is that if one or more packs were stuck preparing, you could simply copy over their data and let the EA App verify rather than needing to download everything again.