I know your exact same situation with brother/sister rivalry, however mine leans in the opposite direction. Think of Ferris Buehler's relationship with his sister. We get along great now that we are older. I actually bought the house right next to her and I get to see her and her family quite often now. Less often than we hope for since we are both busy but it is nice.

Ours is less of a who's better than who but more of a prank war. We have been battling back and forth with a mannequin head for over a year now. I propped it on a broom stick and laid it against her window for her to discover right before bedtime, then I find it in my freezer a week later. Lately though, I purchased 100 DVD copies of The Royale Wedding which is essentially a wedding video of the prince who just got married and I hide one copy every time I go over there.

Maybe if you can't beat her at pinball or everything else in life, you can torture her with mini pranks.