A 190E 2.3L would also be a good choice -- decent milage, no severe maintenance problems I know of, and fairly common, also getting a bit long in the tooth now, so not too expensive.
My perfect idea of a first car for anyone except the occasional truely reliable kid is a junker that barely runs. That way, when they run that traffic light or go too fast on an icy road and spin out into a culvert, you won't hurt so bad since it was junk anyway. Ditto for driving with their foot to the floor with the oil pressure light on.......
Seriously, if she is a reliable kid, a 190E would be a good combination of reliability, safety, and economy.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!