There isn't much difference in the two dependability wise.

Oil changes are critical on modern cars and Chryslers are no exception. Look in the oil cap/valve cover and if one has sludge or crusty crap inside it wasn't well taken care of.

Being a first car I would pay close attention to which one she can drive best. Blind Spots? Which has the best seat location in relation to the controls? Is a 2 door or 4 door better for her ability to see her surroundings?

New drivers are easily distracted and overwhelmed so making sure the car is easier to see out of and comfortable to control will help.

Take her to a lot and have her sit in them, maybe test drive them.

As far as quality and dependability the 1.4/2.0/2.4 4 cylinders are pretty good. They eat thermostats like candy, and they have 2 instead of 1, but aside from that the only other common problem I have had is that the throttle bodies will die eventually. When combined with the 6 speed auto they are just as peppy as a 6 cylinder.

Keep up the oil changes.