Friendship Boxes

I had an idea for the girls to make friendship boxes in the hope they when they are mean to each other that they can go to their boxes and what's inside will reflect what they really feel about each other. The idea is that at anytime they can pop something nice into their sisters box - a handwritten note how special they are, a small toy, a drawing - anything that will make the other happy. When they are fighting they will be sent to their rooms to look through their boxes and hopefully it will make them realise how special having a sister is. Fingers crossed.