Rear shocks rusting out and spring breaking

Having the rear shocks completly rusting out and having a back spring breaking is this a common problem with this car and on top of this having the head gasket leaking?. My mom just took her car to the shop and this is what they told her. The ride of the car seems to be they same other than the sound of the back left shock making noise and its costing almost 2grand and she drives the car like an old person slow and steady.

I just replaced my rear shocks last weekend and the were all rusted and completely shot. I could compress the shock very easily with my hands. While I was under there I did a visual inspection of the struts and they looked to be okay. The original shocks had 97,000 miles on them. Food for thought.....