Standing on a bus

We were on a bus on our way home from the market. Just 5 minutes? on the bus, the little one had wriggled out of my arms and insisted on getting down from my lap. She wanted to explore the bus but I grabbed on to her firmly. The bus was moving and that was not the best playground for the little one. She got tired of struggling and stood meekly beside me. There was this little protruding kerb (just the right size for her butt) at where she stood and I later realised that she was sitting on it... You can see it from the picture, that her knees are slightly bent...