girls carry all sorts of things in their handbags. If pepper spray is seen as a weapon then think of innocent everyday items that a woman would have in her bag that could be used if she felt in danger.
a set of keys held in her hand could accidently harm an attacker if she 'accidently' had a key protruding as she defended herself.
hairspray, something that could just be grabbed from her bag in the panic. That in the eyes stings enough to disorientate any attacker for a moment.
Im not sure of the legalities but in a situation where you feared for your safety then youd use anything to hand wouldnt you?