Thank you for your query.
Post nasal drip
without nasal blockage is uncommon.
Seems like a case of pharyngitis
Gargle with medicated gargle if possible.
Give her nasal decongestants if there is nasal blockage.
Consult your ENT doctor if the problem persists.
If you have any further queries you are free to consult me.
Hope this answers your query.
Wishing a speedy recovery.
Have a nice day.