My baby girl is 6 and half month old. And my baby avoid formula milk she wants only breast milk . But that is not sufficient for her. So her grand mother gives her cow milk for last three days. I m worried about that because cow milk is not good for baby under 1 yr. But baby has no symptoms or allergies in last 3 days due to milk consume. What should i do. Should i have to change formula milk or should continue cow milk