A. Best to have her checked over . Vomiting can be a sign for a wide range of conditions from just alimentary indiscretions, to more serious pancreatitis , kidney disease etc. It is always better to see your vet. If it is nothing serious medications will make her feel better shortly after the visit ensuring a prompt revovery.
A. Considering her young age I would recommend to take her to your veterinarian for a check up. Prolonged starvation in kittens can be quite debilitating and she could get dehydrated very easily. From the signs you described it is quite difficult to understand the underlying reason for the inappetence but it is likely to be related to the gastrointestinal system (as she vomits as well).
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