Hi,
The short history of breathlessness and severe bouts of coughing at night in case of your daughter can be due to one of the following reasons:
Mucus irritating the laryngeal apparatus, vocal cords in particular can cause violent spasms and coughing.
Allergy to something in bed can cause similar problems.
Asthma in rare cases although coughing is not usually severe.
I would advise you to take her to the Doctor to have proper examination, investigations and management as per the cause found. Also see for any allergic factors in the bed or in the bedroom like molds, mildews, dust, mites or so and get vacuum cleaned the whole area, change the linen, curtains, covers.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. T. Chandrakant, General Surgeon