Super. I'd love to hear about the appointment and CT results. And here's a short lesson on 3 part breathing.
Basically, the goal of deep breathing is to increase capacity for oxygen to be taken in and for CO2 to be expelled from the body. Imagine the torso in three parts:
* from the bottom of the pelvic floor to the navel
* from the navel to the bottom ribs
* from the top ribs to the shoulders and neck
Each of these three parts should be affected during breathing. First, your mom can lay on her back (on the bed or floor ... but somewhere she can spread out and lay comfortably). First have her concentrate on her stomach. Ash she breathes in, have her place her hands on her stomach. The stomach should rise as she inhales. The stomach should fall as she exhales. Have her focus only on filling up the stomach and the parts of the body BELOW THE BELLY BUTTON with air. If you see her shoulders rising, she is cheating and needs to start again.

Part 1 complete.
Then, she should take her hands and place them on the side of her ribs. She should continue to breathe into her stomach but this time, she's allowed to increase the breath into the second part of the body --- from the navel to the center of her chest. Have her concentrate on feeling the ribs move out to the side as she fills up with air. Inhale into the stomach, the ribs. Exhale from the ribs to the stomach. Part 2 complete.
Well...you probably know what's coming next. The whole enchilada. She breathes into the stomach, the ribs, and now all the way up into the shoulders. THIS is the full breath. 3-part breathing is also a practice of concentration. It's difficult to even take 10 full breaths like this. So, start out slow --- aim for 5 full CORRECT breaths and then increase a day at a time by intervals of 5.
Do you think that you can do this with her?