If "discomforting" means that the old lady finds herself becoming breathless, it could be that the smell of paint induces inflamation and bronchial hyperreactivity & thus could be a 'trigger' for her asthma.

You could start your treatment by educating her on self management of the condition, identification of precipitating factors, how to avoid them , the warning signs of an exacerbation and when & where to seek help etc.

A good book is Physiotherapy in Respiratory Care by Alexander Hough.