Summer holidays, and with a break in routine and family coming to stay in our three-bedroom house, I thought it would be a perfect time to start transitioning my two girls to a shared bedroom. I imagined lazy evenings of reading bedtime stories with one precious girl in the crook of each arm, goodnight kisses and waking in the morning to find the two of them snuggling together, the picture of Instagramable sisterly affection. The older one has always been a great sleeper, the younger is not – so I thought, now she is 18 months old, she may learn...