Hypersensitivity Pneumonitis. In spo2?

My mother is under the treatment of the above-mentioned disease since 1st November 2016. Her spo2 fell down 72-71 and ever since she is on Oxygen and steroids. Now after her last review her dose is tapered to 6 mg and still on 16 hrs of oxygen. She feels better but still complains of chest tightness while walking. During normal hours her spo2 is 92-93 but when she does some work, like general cooking, bathing it falls to 83-84 but gains quickly. It's been 5 months with this treatment, will she ever be off the oxygen or completely fine to do normal daily tasks without fall in spo2? More than the breathing problem, she is disturbed morally as to will she ever be fine and remains sad and not so hopeful. However, we try our best to cheer her but sometimes we feel as if are we on the right track of hope. Please help. She is definitely showing signs of progress but they are slow and my question is if she will ever be normal again.