my baby is one and half month old and she is very thin, which gripe water can I use for her and which vitamin drop can I use for her weight gain

A. Dont give outside thing without concern of doctor. pediatrician recommend that up yo 6 month baby should on breast feed only after that you can give external food.first of all after each bresst feeding burp.your baby properly it improve digeation increase frequency of feeding . give proper full body massage with good oil it also omprove digestion and so weight gain.