How do a muslim woman pray if she doesn’t have a hijab?

I’ve watched a film based on a true incident where a muslim girl’s plane crashed and she ended up in a forest. She’s got some minor injuries & some of her clothes were ripped including her hijab. So she was all alone & she didn’t have anything to cover her head & her arm. In that kind of situation what should the girl do? She doesn’t have access to anything at all. How was she supposed to pray? From what I’ve read, a muslim woman should wear a hijab in order to perform her prayers.