Tell your mother to follow this technique twice a day. Measure the oxygen level before and after this kapalbhati.She will feel exhausted initially, so start with 30 seconds, and try to increase gradually.Also give her warm water to drink - no cold drinks. The expelling of air from lungs, will help to get rid of some of the liquid in the lungs, and the extra oxygen going in will build up the lung funtion.
Kapalbhati pranayam -(Do it before eating)
Build up your timing gradually.If you feel tired or dizzy, stop and resume after one minute. Push air forcefully out through the nose about once per second. Stomach will itself go in(contract in). The breathing in(through the nose) will happen automatically. Establish a rhythm and do for 5 to 10 minutes twice a day.
My grandmother used to pant. Before she was put on oxygen, she said it helped when my dad put a fan in her room that blew into her face. I think he had it on the oscillating setting. She said it made her feel better.