I would also wonder if the kitten had help with the kill. If it is very young, the mother cat wouldn't be very far away. It should still be learning hunting skills from it's mother. So it may have learned that the birds are a food source. Your friend sounds like she knows how to care for the kitten, so it sounds like a great option for you.
I thought that rabies is extremely rare in the USA. Though that maybe only talking about deaths.
I thought that rabies is extremely rare in the USA. Though that maybe only talking about deaths.