Ha ha...no, if her gun weren't going off it was operator error for sure. She was doing something (or many things) wrong, and we could make a long long list of possibilities. Or it may not have had a good lock on it. 3-4 times to get it to fire is WAY out in left field. A good flinter should be 100% reliable, when everything is 100% right.
A flintlock will go off everytime with total reliability, IF everything is right. An experienced flinter will have everything right when he pulls the trigger.
In my opinion, the ADVANTAGE of a flintlock is that you can visually tell if everything is right.
With a cap-lock, you can't see beyond the nipple and into the maincharge, and can't always tell if a cap is dead. Can't SEE or KNOW if there is a blob of oil soaked powder, of a clump of fouling between the nipple and main charge.
On a flinter, you can see if your flint is good, set right, frizzen clean, pan filled, prime dry, and you can usually see right through the touch-hole and into the main charge, or you can run a pick through the hole and feel if the powder is dry. Everything can be seen and checked. If the gun does not go off, something was not set right, checked right, or seen to. Strictly operator error.
Flintlocks probably require more stuff to shoot. A good flintlock is in no way troublesome, but they are "high maintenence", you must pay attention to many more details. But there are no true "mystery" miss-fires with a flintlock..if it fails to fire, the shooter failed to pay attention to some detail.
Generally speaking a flinter is less reliable in a heavy rain, although that can be addressed and minimized also. But that would be the only disadvantage I could think of.
Rat