[PLMerite]

Whistle? No way. Carry one of these:

Easy to operate: Insert, twist, remove. Run.

[cloudmountain]

Kicking a man where it REALLY hurts is always a viable way self defense. But she has to be ready for his real anger. The kick better be HARD and ON TARGET.

[NorthMountain]

Cheap, and they don’t set off metal detectors.