Yup, Fat Princess makes Raiden look like a housecat, and I'm seeing more of them with each passing day.
I personally think that she just needs to lose the super armor on her square attacks, unlike Big Daddy, her moves already have a great reach, it makes approaching her unnecessarily difficult since she'll always win out.
Online lag plays to her advantage too, when I figured out what they were doing I just figured "block her attempt to confirm as I wake up, right"? Apparently the server doesn't get that information quick enough. Your character starts at a neutral frame which the player used to keel me over with her neutral square, getting knocked to the ground was a death sentence unless it was a platform I could drop through. Removing her super armor would be a better solution than spending hours on the netcode, so at least someone can attack her before she tries to pull that off. It's kind of like Raiden's chain grabbing: technically there's a way out, but the milliseconds of input lag playing online won't let that happen.