Honestly I would go to the shelter and save a cat from there, they are putting one down usually every day I'm sure of it unless it's a no kill shelter. Those animals need your love and care just as any other animal does, by getting one from the person on the farm you are just supporting the bad breeding habit she is allowing her cat to have, that and well who knows what kind of diseases they are picking up from being out there. A cat from the shelter will more then likely be fixed already or they will give you a voucher to get it fixed, that way it will save on reproducing and you won't have any issues in the future with that happening in case it gets outside. Support the kitties who need homes from the shelter, go with your gut and everything will be fine, let alone that kitty will be saved and love you forever for it