I expected Charlotte to start the "mine mine mine" stage as soon as Sam was old enough to hold a toy - and it's gone as expected. The lessons on sharing, the breakthroughs when she brings a toy to Sam, etc.
I did not expect self sacrifice.
Tonight, I put Charlotte to bed after reading two books and cuddling for 15 minutes. She howled and cried as I turned off the lights and closed the door. She stood at the door and begged for her blanket so I opened the door to find it. She woke Sam, who started crying from another room. She ran back to her bed and while crying told me to "go take care of Sam". She said it over and over. Like she needed me but it was more important to take care of Sam.
For a two and a half year old that's an awesome concept. I'm so proud of her.