higher and bottom norms

How would you naturally phrase the following sentence?

She isn't overweight. As long as she grows in accordance to her weight, she'll be fine but if she puts on weight but doesn't grow in relation, then she could no longer be in the norms in terms of weight. The bottom norm for a 3 month old baby is 55cm and the higher norm is 65cm. The bottom norm for weight for a 3 month old is 4,500grams and the higher norm is 6,500grams.

Thank you