I have adopted a general plan for what to do whenever I find myself in similar situations.

1. take a quick but comprehensive census of your potential assets - this may involve you emptying her pockets/purse what have you. You never know when a holocaust cloak will be useful, for instance
2. Create a circle around her. Salt would be best but a line scribbled in the dirt is often surprisingly effective
3. Power up the circle
4. Observe

And that's it! 99+% of the time you will figure it out. Good luck!