Good fair question - no idea why some folk appeared to give you the thumbs down for it - have given you a thumbs up and await a useful answer.
Not necessary to be fat, she could be paralyzed and needs a special car for the wheelchair !!!
Thanks, no wrong with fat people, and we must be careful that our comments don't hurt others indirectly .
Would the literal translation of this sentence be, "She does not fit there in that car?"
No, in this case ci is part of the verb "starci" (stare + ci); stare usually mean "to be in", starci extends the meaning a bit with "to fit (in something)", "to go along (with something)". These verbs are usually conjugated with their pronoun, i.e. io ci sto, tu ci stai, and so on.
I wish a could bookmark such useful comments using the Duolingo app but I can't. I also wish a could give you a lingot but the app does not have this capability either.
My answer: " She is not in that car" was accepted as correct, and sincerely makes more sense that the one DL has as the right one. The Spanish translation: Ella no esta en aquel automovil" corresponds almost completely.
Be careful when using Spanish as a comparison, they don't always match: in particular, the Spanish "estar" and the Italian "stare" have different rules of usage. That being said, your sentence makes sense in some regional variants of Italian, but it's not really mainstream.
So,we still don't have an answer to the original politically incorrect but valid question. Is s/he to fat for the car?