I am amused now too!
A gun gives a physically weak female pensioner a better chance to protect herself from a muscle bound powerlifter than she would if she had no weapon. As I've pointed out, there are times when pulling out a gun has stopped an unarmed attack, whereas if there was no gun, the victim may have been beaten up anyway after handing over his things, or may have chosen to fight the attacker and injured either the attacker, himself, or both.
Have you looked at the video above Donthave? Obviously not. There is a young guy on there who is trained in firearms, who has used many different weapons. In a situation where an attacker stormed into a meeting room even he could not get out his weapon quickly enough to disable the attacker. It's a very interesting video. Watch it.
Yet some frail pensioner is going to be able to protect herself against a muscle bound powerlifter? Her reflexes are sharper, her actions quicker?
The production of that gun resolved the situation peacefully, with neither party injured other than the pride of the would-be attacker being a bit dashed when he was forced to leave.
The last sentence of yours nearly gave me cause to choke on my tea. So a little old lady gets out her gun (watch the video - it's impossible to do so in the time required, and that's younger people) and tells him to stop taking £4.50 from her handbag. Muscle bound aggressor is suitably admonished, realises the error of his ways, feels a bit dashed but goes home to nurse his injured pride.
Now I know you're having a laugh, I'm not taking anything else you say seriously!