Over the past 5 years I have had at least once per year the following. Usually low ability slow pitch girls league.
Batter swings at inside pitch. Ball hits safety grip and leaves bat, but as she finishes the swing the barrel end of the bat hits it again (double hit). This is a foul ball if I'm not mistaken. Also had one fast pitch batter bunt. Ball went straight down, hit plate, came straight back up and hit bat again while it was still in her hands. Foul ball again if I'm not mistaken. I just can't believe this bazaar thing keeps happening to me.

You are right on the money, as long as the batter is still in the box and has done anything to intentionally hit the ball twice, it is a foul ball.

Picking on you, but I believe if batter does anything to
intentionally hit the ball twice, she would be out.

However, I hope you meant what I really think you did.