"I don't feel"

So, now that Madison won't nap, I am trying to teach her quiet time where she reads books or plays quietly in her room...QUIETLY is the key word here. It's not working...I hear Mommy, Mommy, I want to get out, I need help, I coming, Wake up Abby. It's this last one I want to address. Madison loves her sister so much that if Abby is napping and Madison is not, she wants Abby to be awake with her. She loves to play with her. So, during 'Quiet time' (oxymoron right now) Madison was upstairs screaming for Abby to wake up. I put Abby downstairs hoping that would be far enough out of Madison's lung reach, but NO. Abby was awake screaming by the end of the 30 minutes of screaming. I was upset with Madison and tried to explain, "Madison, what if I came in here screaming when you were trying to sleep? How would you feel?" To this she replied, "I don't feel." I was silenced by a two and a half year old. What could I say to that?