The Sims 3 - Reset sim, still having trouble

She wasn't using the sink. I wish she was because that would certainly solve my problem. She was reading a book to her child on the floor in front of the sink. Why they decided to read it there is beyond me -- they're sims. But after she stood up, she froze in that spot. She wasn't looking around or anything. It was as if the sim froze but everything else in the game kept moving. I know sometimes if a sim gets stuck they can look around or make motions letting you know they can't move or whatever. So now it's as if there's an invisible sim permanently stuck that all of the characters can see, but I can't. 

I did try deleting the tiles in that spot in build mode (because I realized after I made the thread it wasn't just one tile, but three), but it didn't work. It kept telling me "Floor tile required by object." And if I shift-click in live mode, it asks me if I want to buy or build on the lot. 😕mileyfrustrated:

Do you happen to have any other suggestions? I know it's not going to be the end of the world and I could probably sell the house and move somewhere else and maybe back in, but I really didn't want to do that. It seems like a waste of time... 

Thanks in advance!