COPD, chronic obstructive pulmonary disease, develops over time and includes several diseases such as chronic bronchitis and emphysema. As the disease progresses, the patient has difficulty getting air into (and
out of) their lungs. Sadly, smoking only makes the situation worse. You have seen this first hand.
This disease pattern, from a hospice perspective, is especially difficult because the patient has periods of stress (we call that exacerbations) where they end up in the hospital, and periods of "remission" where they appear to improve. There are a lot of ups and downs. It is especially hard for a physician to determine a six month prognosis, which is needed to refer to hospice services, because the patient keeps getting "worse" and then, "better."
You state your mother is now in ICU on a BiPap, or Bi-level Positive Airway Pressure, machine. The BiPap is helping her get more air into her lungs, as she is unable to do so herself. The mask is usually not comfortable for the patient and generally, the oxygen liter flow is quite high. This means she needs to be where she can get the amount of oxygen her body requires, and not every facility (except the hospital) can provide that. Add to that the exhaustion and fatigue and frustration she must feels, we get a sad picture for end of life.
You might speak to your mother's doctor, or nurse, regarding providing morphine for her pain and to help her breathing. This would be part of comfort care. This would also be an appropriate drug at this point. Keeping her comfortable and safe may be the best course for her now.