It's totally normal behavior for a kitty or even a full grown cat. Our cat "moms" on blankets and the back of my hand, suckling behavior that's lasted 3 years. He was abandoned by his birth mom at 72 hours, but that really doesn't have all that much to do with it, I"m told, Enjoy it.... :>)
I've had kittens do that to me too. Usually they were taken away from their mothers at too young an age.
Our 80 lb Akita still does it - on my hand.
Sorry cat people for mentioning a dog in this Forum = )
My kitten use to do this too -- it actually started to hurt and I would get little kitten hickies. I just redirected he to the nook of my arm -- I'd rest him on my forearm and he would suck my upperarm (opposite side of elbow.)
He did it less and less as he got older -- only if he got upset about something. I think it gave him comfort. Anyway, he is six now -- hasn't done it in 4 years -- they definitely outgrow it.
Good Luck!
Perhaps you just have a very kissable neck. :)
It's common behavior. If you don't mind it, I'd let kitty partake. After about three months I may say "enough!" though and gently try to encourage stopping. I've noticed cats that suckle up to even six months off their mothers. It seems strange to me, but they seem to turn out to be very affectionate animals, so I tend not to dissuade the behavior.
It does make for a somewhat emotional demanding cat, though...which sounds nice in theory, but can be very taxing if you have a busy life!
Does the kitten eat or drink on its own? If not, it may have still been nursing and needs to be bottle fed. But if it does it on its own, it is just her way of comforting herself. And you are definitely her new mom! One of my cats still kneeds into me and does a sucking motion...but has become much less. Good luck with your kitty!