Brief Answer:
Weight of 7.5 kg is much below the normal limit

Detailed Answer:
Hello

Thanks for asking on this platform

Weight of 7.5 kg at this age is much below the normal limit.
It is good to know that she has achieved the developmental milestones well.
I would like to know if her diet is adequate or not,her bowel habit is normal or not.
She needs proper physician examination to rule out any underlying disease causing this failure to thrive.
I would suggest you to get her evaluated by a pediatrician for complete physical examination .
If clinical examination is normal,I would like to increase the frequency and amount of feed.Also add some ghee or butter to meet the caloric demand.Most of these children has some other nutritional deficiency like iron defence, calcium and multivitamin deficiency.
Discuss with your doctor for need of supplementation of multivitamin and multi mineral syrup for better growth.

I hope this helps.
Please let me know if you have any more query.
Regards

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Brief Answer:
Hereditary prevalence of thin built is unlikely

Detailed Answer:
Thanks for follow up

There are various studies which proves that there is hereditary prevalence of obesity/short stature/cardiovascular risk factors,but hereditary prevalence of thin built is not known.
It has been seen that eating disorder is a significant attributable factor rather than illness or hereditary prevalence.
Although basal metabolic rate differs from person to person but that can be managed with increased caloric intake.Height has significant hereditary prevalence so I would suggest you to monitor the growth of baby(height and weight of baby according to growth chart based on mid parental age).
So again I would request you to increase the caloric intake of yourself and baby both.

Best regards

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