Thanks for your query,
seems to be viral in nature as you mentioned everyone in family has cold and cough
.and will take couple of days to settle.
I suggest you to give paracetamol
every 6 hourly till fever is more than 100F.give her plenty of fluids,coconut water,fruit juices and semisolid food which she is taking routinely so as to boost her immune status.
In case symptoms persist get her evaluated by pediatrician
for proper management
Wishing your baby good health.