Answer:
It would be working properly and providing her energy for her daily activities.
Explanation:
Hello!
In this case, since her oxygen is actually working properly, it is going to be travelling throughout her entire body (via blood) and therefore carbon dioxide would be released as the exhalation product due to cellular respiration carried out in the alveoli which provides energy for her daily activities.
However, the intrusion of different molecules to oxygen into her cells may affect the rate at which cellular respiration is carried out and therefore she may feel tired because such process provides energy to the body.
Best regards!