Hi...my vet said that it is possible to have kittens born a day or two apart. It has not happened yet with my cats, but apparently it is possible. I would not go sticking my fingers in the kitty if you do not really know what you are doing. That is a job for the vet. As long as kitty is feeling ok, nursing and eating (I offer mine a dish of warm carnation milk mixed half and half with water as soon as birthing appears to be over) I would not worry. See how she is in the morning. If she is not having pain, don't worry....just watch her. Your vet is only a phone call away.