Kittens need to eat a lot and often in order to grow. I never look at recommended feeding on packets. I would not be concerned about that unless her poop was soft of runny.

A few weeks is a long time if she hasn't had a vet check since leaving the breeder. If you have kitchen scales, pop her on to see what she weighs. It is always advised to take your new kitten to see your vet within a few days if getting them home. This proves to you that they a healthy and any undesirable problems are picked up ASAP. It s not unheard of for breeders to have 'issues' in their home that dies not necessary show as a problem until the kitten leaves and is put under stress. Unless these issues are diagnosed quickly the breeder can claim that the problem did not come from them.... This is just one example but their are lots of possible scenarios. I breed and I still advise to owners to take their kittens to their vet.

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Lollo