Eaglescout:

A quicker method is to thank her because you now have one more person you will not help in an emergency.

If she asks why, tell her if she doesn't care enough to prepare for emergencies, why should you care for her and have to divide your supplies with someone who didn't care enough to prepare.

Yeah, I know it is cruel and not "politically correct", but the point will come through much quicker and you may save her from future problems.

Bountyhunter