And look! It has grown wings! It must be close to maturing.
Young dragons are relatively defenseless. They are born with relatively soft scales, which are shed and replaced with harder ones as the hatchling matures. Once a hatchling’s wings grow in, it marks the beginning of maturation. At this point they are often capable of hunting on their own and are usually left alone by their mother.
Fox was always small. She never quite managed to grow. Nobody but Fox knows what happened to stop her from maturing, and she wouldn't ever tell. Because of this, the other dragons get a little confused about things, and still treat her like a hatchling, even though she should be adult by now if she hadn't been seemingly frozen in time.