This is a tough situation. Many times if you open the top sash of a window the bat will often find its own way out. We have had a bat in the house 3 times. One time we caught it in a towel and put it outside, another time it was a victim to one of my cats. Cat jumped straight up 6 feet and brought it down. Poor bat did not survive. 3rd time we again caught it in a towel after trying the window thing. It did fly toward the window but landed on the curtains and just sat there so we did the towel thing again. Does she have any neighbors she can call on for help?