The poor wee thing!! Taking panadol type cough mixtures can help with coughs. Codeine also stops coughs, but it's hard to get now.
Are all of your daughter's vaccinations up to date? It sounds to me like recurrent whooping cough (pertussis), or she could even have TB, or a resistant strain of TB, which is on the rise again in many countries. Kids can be vaccinated against whooping cough and still get re-occurrences of this illness. If it is TB she needs to be isolated and she needs a chest xray for a start, and you all need to wear masks as TB is a serious, infectious illness.
Try to get her back to the doctors.
I have said a prayer previously for your whole family on your other thread re the same thing. I'm saying another one as I type *prayers sent for you through the internet* Amen.
Let us know how she goes!