To be fair, she was doing fine until she followed her impulses.
But "It's only normal to be kind to those younger than you, right?" basically says she was following her impulses in being nice to start with...
It's probably more that she's being friendly, but also super-casual, can't control her strength, and likes to play rough. Keep her in a sedate setting like a restaurant, and she does well, but when it's time to play, she'll fling him halfway to the next city.
