ball hitting the knob of the bat

I had an odd play this weekend doing a 12u low level Rec. FP game. Most of the girls just starting in FP. Pitchers just learning to pitch so the ball is not being thrown that fast. Ball is pitched batter drops her bat parallel to the ground and the ball hit the knob of the bat and rolls about six feet fair into the infield. I point into the infield fair ball. The batter just stands in the batter’s box both base coaches come running asking the girl if she is alright. She tells them I’m fine the ball hit the end of the bat. They keep asking her if she is Okay. She tells them again I’m fine and I’m still pointing fair ball the pitcher is just standing there with the ball in her hand. Finally I say, gentlemen that is a fair ball and they look at me and smile. I say again gentleman that was a fair ball when the first base coach touches the now batter runner on the shoulder and pushes her telling her to go to the base. I call dead ball. Coach I now had an out you helped the runner. He said what? Coach that was a fair ball and I told you two times. You helped the runner by pushing her and she is out. He said I though you called time. I told him you will know when I call time I pointed fair. He just walked off and the game went on.