I just saw your post now -- Sue has absolutely said she was contouring with dirt. She was also tending the fire a lot, but that's not unusual and most people would wash the soot off. Sue's face is dirty by design.
I also think she's more the goat because she's very obvious in her social relationships -- everyone knew she was ride-or-die with Caroline so they can't "get in" there and also because she was so resentful of Kyle. She's prickly and I think people don't consider her much of an ally for that reason. Rachel is the only one who seemed to know how to work with her post-Caroline.
That said, absolutely age and gender play a factor there. But I don't think it's the only reason people think they can beat her.
