I see. I don't have the bike here at the moment so I can't comment specifically on parts. This hadn't happened when she first got the bike. She had a fair bit of trouble with it (threw a chain, accident, tourists that don't understand crosswalks) so maybe the derailleur took a knock. I know for sure that the shifters only ratchet when tightening. Tomorrow I'll have some time to sit with it and try some stuff so all of this advice is very helpful. Keep'em comin! Thanks everyone