Didn't mean to drag this thread off topic... but here is a vid of her breathing. It did get worse when she was pushing hard, but this is after she had calmed down some (I have audio of when she was breathing harder). I can see now that she does slightly open her mouth upon exhale, and then breath in through her nose. (Needs to be turned up a bit to hear it, but it is clear.)

Checkered Garter - Breathing - YouTube