My baby is unable to gain weight

My baby is 6months old and she is just 5.75kg weight and as per I know the things she should be doubled her weight when compared to her birth weight and her birth weight is 3.7kg. Now iam feeding her with zerolac,cerelac and some fruits like banana,apple(only cooked not able to digest when feeded raw). Please suggest me how can i take care of her to gain weight and she is soo thin even let me know how can i make her look bubbly.....and healthy anyway...

[Renee Radenberg]

Her weight is just below the 5th percentile for her age. As a guideline for a 6-8 month old child should eat the following: Breast-milk or Formula (6-8oz) 3-5 feedings a day. Starch 2 feedings a day – Infant Cereal (2-4 Tbsp), Crackers (2). Fruits or Vegetables 1-2 feedings a day – (3-4 Tbsp), Stained meats 1-2 feedings a day (1-2 Tbsp). Hoped this helped you.

[rose2121]

My baby is almost 10 months weighs 16.5 pounds and is 25 inches tall my two older daughters were also small she's breast fed on demand eats all day drinks plenty of water she has about one or two bowel movements a day she's very happy and energetic but everyone says she's too small