If you look at the goriest panel I did in Defiance, you'll see why a boot and even sock might go astray.
Still, I only really go by what I see in the film... and given the time you see her in ISOLATION isn't necessarily CANON (though clever)... it's pretty free to interpretation. I mean...
Anyway, you want to see how she died*, bug Dark Horse to let me do my ALIEN: DESOLATION book...
*according to my imagination