Vertically unchallenged

What would our 2D friend do if they encountered an obstacle without knowledge of the third dimension, they wouldn't be able to go around. They could try to tunnel under, leaving up support gates behind them to prevent a collapse, but it would be easier to just jump right over. After all, if they are infinitesimally thin, then they should weigh nothing at all, and should be quite proficient at jumping high. If you look closely, you'll see she's actually carrying a vaulting pole for this precise purpose. We could also help, of course, by moving our friend through the third dimension. I can help her get to places that she wouldn't be able to access otherwise. Just remind me to move her back shortly. I'd hope for her to get stuck there.