A few questions...
 

Daughter #2 just purchased her first vehicle. It is a Jeep Grand Cherokee Laredo. '99 with 86,000 miles and it is in excellent shape. She is tickled pink and I'm surprised how nice it rides. It is a 4.0L I6 with selec-trac. Before we brought the vehicle home, it had an oil change, all new brakes, lower ball joints, and a front end alignment. So could someone please tell me what else I should probably have checked or done to the vehicle to keep it running smooth. I'm told those straight 6 engines are practically bullet proof if taken care of. So what should I have checked next? Maybe take a peek at the serpentine belt and does the transmission fluid need to be changed. These are questions I need answered. Any help would be appreciated. Thanks in advance.

Yes It couldnt hurt at all flushing all the fluids and going fresh, It's very beinificial to any vehicle. Along with a basic tune up, Plugs, wires, filters etc etc you/she should be good if you are not having any issues with it.

i think transmissions are like recommended at 75,000 to have the fluids changed if it hasn't yet. and yeah just basic stuff

most cars if taken care of will last... as stated above dont hurt to have fluids checked filters maybe plugs n wires.

I never thought about the plugs. Thanks guys.