Late 90's Cherokee Sport Q?
 

Hey all! My cousin Nicole wants to get a late 90's Jeep Cherokee Sport 4 cyl. 4x4 as her first car, but her mom is concerned that 4x4 components are going to start breaking and costing them a lot of dough. Are there any known common problems with the 4x4 systems such as transfer case or front diff failures, or are these things fairly reliable?

Thanks in advance!