When theres only 1/2 bowl of cereal left in the box?
Hi, lol funny situation, but your 12yr old should know that it is ok to eat the 1/2 bowl left inside the box she should set a good example to her sister and if she was still hungry she can open the new box and eat another portion from that. Another solution: is that you can put half the 1/2 of cereal to each of both of their bowls with the mix of the new box.