Hello. First if all, cough and cold is not abnormal at this age even if it happens every 1-2 months as kids catch the infection more compared to adult due to small age and lower immunity. More important, most of the cough and cold are viral related in which antibiotic has no role, so stop giving antibiotic so frequently.
Continue lots of green vegetables, fruits, plenty of fluids.
Next Steps
As her age will advance, her frequency of catching infection will decrease.