Advice for teaching my cousin?

I am trying to teach my cousin and two of her friends. My cousin is about 7 years old Korean age, and her friends are like 10 and 12. I usually teach high school, so this age is a bit confusing for me.

Most of the things I see on these boards or the net are for big classes, not my small group of three.

I can't really do competitive games, because the 11 year old dominates ruthlessly any game I try to play. My cousin gets frustrated and starts whining and one time even cried.

(at this point I think to myself that  I'm glad I teach high school, and then I realize it's not too much different hah)

The only things that have really worked for me are like completely luck based games (like Bingo) or cooperative games (like charades). My cousin still has a ton of trouble remembering the things that I teach her.

If somebody has some advice for fun, cooperative activites so that my cousin can learn SOMETHING it would be much appreciated.

It would be work for you, but battleship would work out nicely to teach vocabulary.  You'd have to thouroughly preteach the vocab to all three students.

For the first two games have the little one be on The 10 year old's team the first time, then on the 12 yearold's team the second time.

Then for the third game, the 7 year old should be familiar enough with the vocab to have a battle ship sheet by herself.

This thread might help: Small After School Classes