Mine too. Can put whole fist in somemore. Once, she was enjoying her fist, and she wanted to take it out and her finger got stuck. She cried in frustration. It was just soo funny lah her expression. Hehhehehe....
Now she can suck her fist till whole face wet. I guess its the drooling and sucking fist phase.
I always try to pull away her fist whenever she puts in her mouth. Sometimes I just let her be lah. I gave her teether, she don't wanna bite. So its either her fist or my thumb and she can suck till got sound.
It's part of development phase bb go thru with the knuckle sucking?