I had never seen Addie even attempt to sit upright on a regular belt swing before. Until Tuesday. There aren't any swings at school (other than the giant platform one in the therapy room), so it's not something she's been focused on during recess.
On Tuesday after school during our usual backyard routine before lunch, she had me sit on the swing and then signed for me to get moving already. I thought she'd climb up on my lap or head over to her slide. But instead, she watched me from the front, from the sides and from the back for a good 10 minutes or so while I narrated my amusement ("straight, bend, straight bend, I'm pumping my legs, straight, bend, it makes me go, straight, bend..."). At the point of her choosing, she booted me off and requested that I help her sit upright on the swing. Normally she's belly down, winding the ropes so she can spin out. No spinning on Tuesday.
The second we were both satisfied with her position and grip on the ropes, she started straightening her legs and bending them alternately. Not at the cadence that would actually get her a good even swing - skipped a few switches, but she gets that her legs control her movement. And she's pretty pleased with her clever self.
Here, have a look.