I have a calf that is only nursing on a small extra teat on the back of the bag. Can she get enough milk from that to live?
What you have is called a "supernumerary teat," and some can give milk -- usually not enough for a calf to live on, but some. I would be very worried whether this calf got enough colostrum.
On dairies, we routinely remove these teats when the animals are still calves to avoid problems when they get on the milk line. I don't ...