There was a commenter on the article that said it didn't look fat enough to trap her.  People so often seem to forget you can drown in mere inches of water.  People also underestimate the amount of panic that can set in when trapped, especially when underwater. I have to remember that I have training on how to escape a drowning victim clutching at me from lifeguard training. And being taught how not to panic. So, I have to remind myself that escape wouldn't be easy for some. In shallow water there are techniques for rolling with a casualty with a suspected spinal injury too, and maybe rolling might have saved her life rather than pushing against the trapping weight. But that's easy to say after the event.  More details are needed, I'm just guessing without knowing more. http://www.weather.com/health/news/types-of-drowning-you-need-to-know