Heather is usually on the attacking end of Conquer the Castle, so Selkie may have a fair shot.

↓ Transcript
In the first draft of this sequence, Heather and Selkie were playing a co-op video game together. I changed it to an outdoor activity because it felt like I was forcing my own interests on Heather and Selkie. Heather doesn't strike me as the kind of kid who likes video games much.