one of these things is not like the others

How do I even know that Sesame Street song when I didn't have a TV while growing up? what a mystery!

Anyways, I would describe our family as pretty physically active. Last week Kevin ran 25 miles. I ran about the same plus did 4 Jazzercise classes. Brakston ran, lifted weights, went wakeboarding, and played soccer and basketball. Alec jogged quite a bit and even went and lifted weights with Brakston. McKayla ran about 40 miles, did conditioning for soccer, went swimming, and went out on the innertubes behind the boat. Chandler rode his bike, went running, had soccer practice, built forts, etc.

Shanley? not so much.

I made Shanley run 2 miles one morning and you'd have thought I was torturing her. There was some foot stamping, lots of complaining, and quite a bit of attitude. I'm not sure she's totally forgiven me yet.

Can you guess which thing is not like the others before I finish my song?