I totally understand your concerns about yout granddaughter health.
Your grandaughter is experiencing what we call :
bronchiolitis which is common during this age group and with the exact symptoms she is experiencing.
the following points should be taken into consideration
1- Even though this is bronchiolitis, we should always rule out the possibility of
pneumonia, and thus a chest X-ray should be done along with a
Complete blood count CBC.
2- if pneumonia is rule out she must be started on High flow therapy with a high flow device that can provide medical grade vapor is an important part of the management of bronchiolitis. Nebulized or inhaled
salbutamol might help her symptoms a make her breath at ease.
3- if pneumonia is suspected she must be started on antibiotics
4- make sure your granddaughter is not febrile since this increases the chance of her having
febrile convulsions too.
as a summary, your child needs to be evaluated based on the history you provided and actions must taken to help her breath well. Go to the pediatric emergency department if possible.
Regards