my daughter is 5 months but she is very lean ow to make her healthier pls suggest me

A. hi how you conclude it ? from physical appearance only? if yes then please don't do this because for a child,it is not important to look Chubby,it is more important to stay happy and active then any other things. so please continue with breastfeeding. for Healthy weight gain ,feed your child on each breast at least 20 minutes so he or she can get full fat hindmilk well.