When under influence of earth’s gravitational acceleration, my child has a weight of about 70 pounds. How is it, then, that her apparent weight doubles when under the influence of my bed’s gravitational acceleration?

Last night, Rachel fell asleep in my bed. When I was ready to fall asleep, I found her taking up nearly the entire bed. I leaned in with a shoulder to slide her across to the other side but couldn’t make her budge. It was as if she had doubled her weight.

I know its not possible but for the life of me can’t explain why making a sleeping child budge is nearly impossible.