I'm not sure why this happens, but I am also seeing this with EA harvestables, and a few buy items created by EA. I do use mods, but not CC because I don't feel like dealing with every time a patch is released. There are several things that show up as modded even though they are not.
Now to your issue, but test this out first to see if this is correct. Save Natasha to your library with any other aspiration, but not the Grilled Cheese Aspiration. Then start up a new game save, and with your first sim bring up Natasha to CAS, and put her down in the new game save. Since she already has unlocked this aspiration, it should be an option she will still have. You don't have to keep this game save if you don't want to, it was just for testing purposes. If you find the Natasha still has the Grilled Cheese Aspiration, you can just make a note to let others know what is going on. That is if you are wanting to upload her to the gallery.
