My child is almost 6 months and has been having frequent (3 or 4x a month) cold and flus which is lowering her appetite and she cant sleep at night. ?

Doctor can evaluate: If a baby keeps getting colds or similar illnesses, but otherwise had been doing fine, it sometimes is time for the baby to isolate herself from other people except the two parents... and see what happens over the next 2 months. Infections can be transmitted by sick people (sneeze, cough, kiss, touch, etc...) or by a well person transferring germs from a contaminated object or sick person.