I do not know about the indefatigable brother, I think he got tired) Sisters certainly are all on the positive. The way they got caught by their mother and the brother hid, it was well thought out. But then when they went on and the mother, or whoever she is I don't know, was sitting next to them, I didn't understand why they did that. It was nice to watch, especially the sisters, the brother was kind of passive in the clip, he was almost never even shown.
The chick decided to teach Russian to her classmates. Good for her. What's the best way to make the words memorable? Our chicks have a way - show them on their own bodies. Woo-ha-ha, that's why foreigners know our words well - motivation is cool!