I make her younger to the age of 9 when she had her first period. I remember that day. She ran up to mom in the living room and said out loud, "Mommy, I'm bleeding!" My mom then said, "Where honey?" I then heard her whisper and point at her pussy, "Down there!" I laughed when she did that. My dad asked me what I was laughing at and I told him I would tell him later. Once they left to go to the store, before I said anything he agreed that she should have not said she had her period out loud.
Back to now with age changing sister, "Well if you want to be older, you have to do something for me!"