E.M.
My advice is to consult with an allergy specialist. Asthma can be triggered by allergies. An allergy test can get to the root of what may be causing the asthma. Things to think about prior to her appointment with the allergy specialist; have you made any changes recently such as getting a new pet, moving to a new home, is there a smoker in the home, have you introduced a new food. Any of these things could cause asthma.