Who is she?

That is Byakuren Hijiri.

She's is/was a Buddhist monk. She usually isn't drawn with a bald head, though..

That's not Byakuren.

And her sexiness decreased by 9 (Current: 990)

Truly A Buddihst Monk now.

Not yet. Her dress.

Mr.Obake said:
Not yet. Her dress.

Alas..
If you remove that we wont be able to know its her anymore thou