Wise Woman is a woman with very wise knowledge.
She warns the gang by saying "Beware, Evil walks among us", referring to the Headmistress. When the Headmistress is killed they mention her saying she was right. She is outside when the acid rain starts falling and makes it to the front door/elevator and goes in it. It only fits 5 and there are 6. She then sacraficies her life by letting the other person take her spot in the elevator. When she steps outside of the elevator the acid rain starts landing on her and sizziling. She jumps around and then falls to the ground. Later when they are totalling up the number of survivors she appears saying "I'm still Alive". Everyone is shocked but glad. She says with her wise knowledge that she discovered the rain can't burn through skin but only stings. She then reunites with everyone. At the end of the film she appears at the grand opening.