Dull knives are more likely to slip on whatever you're cutting (and cut you instead).
They're also more likely to need more force when cutting which means less control.
The knives I consider dull will absolutely cut me if I do something dumb, and I'm much less likely to do something dumb when the blade goes straight through what I'm cutting without having to use any force.
I guess it also depends how and what you're cutting. I sure wouldn't try to julienne carrots with a knife that doesn't easily slice through the carrot.
But - if the knife slips and a large force is applied at the same time - then you will get a large cut.
If the knife slips and a small force is applied, you will get a smaller cut.
If the probability of slipping is the same for sharp and dull knifes, then due to the forces applied, the cuts you get with a sharp knife are less dangerous.
It sounds like she literally has no idea how to use a knife.
Is she doesn’t want a knife which can cut things, Butter ‘knives’ are probably more her speed?
What was she even using the ‘knife’ for before if it couldn’t even cut her? Spreading jelly? Slicing cakes?
Not to be snarky, but it’s possible a couples class which covers things like how to use a knife safely might be a fun and enjoyable way out of this.
Zero chance of cutting meat, or 90% of vegetables.
Have you tried that or are you speaking in principle only?
