The C220, and other 4 cylinder W202 cars, are supposed to be some of the most bulletproof and reliable cars MB has made in a while. The wiring harness is not an issue for 4 cylinder cars. It is an issue you get on the M104-equipped 6 cylinder cars, so you're safe there. The only thing you really need to watch out for are the 5 speed automatic transmissions (722.6) in the first year or year and a half they were released. There is a lot of information on this board about transmission failures. I think it is 1997/1998 that has the transmission issue, but use the search function to confirm.

The one thing you will have to accept is that these cars require more maintenance than your average Honda or Toyota. If you do the maintenance they'll last a good long time. If you think your daughter will be good about doing the maintenance, then I think it would be a good choice of car.