Ruthie just seemed at a loss of what to do with her feet... they had always dangled, but it had been different, with her legs froggy style off of either side.
She couldn't cross them, short things as they still were back then, as they didn't fit in front of her on the MA, so she would prop her feet on the front seat, which led to kicking.
In the Regent, even though it had more space and she COULD cross her legs, she chose to stick them straight out... and kick...
in the Radian, though, because it was slim enough, once her legs were long enough to do it, she froggy legged in it, with her feet flat on the van seat.
With the Nautilus, initially she always sat with one leg curled up and one hanging... and she would kick her heel against her own seat (BUT NOT AGAINST THE FRONT)
Now that she's older, though, she just lets them hang.
So I think it may be an age thing.
She couldn't rearface anymore for good because of her weight at 2.5yrs... and there was a big difference between then and 3, and between 3 and 4.