Teaching kids to cook, AND/OR do things on their own is tricky business. But it's got to happen or independence is an opportunity missed. Shit happens. Stuff breaks. What you thought would happen, did not happen. These are all parts of daily life, for both kids and adults. And kids need to get used to it too, not be kept in the dark until they are left alone to deal with the issues at hand..
Setting your kids up for failure sounds completely inappropriate, but they need little tastes of it now and then in order to fully mature and be prepared for the real world. So many parents have a hard time with this concept and I do understand the issues that surround it, but I just cannot let our kids down in the long term.
We have to let them try things on their own and fuck up! I have said for years to my step-daughters that mistakes are actually little gifts in their own form. You learn quickly from mistakes out of embarrassment or shear fear and therefore are less likely to make that same mistake again because of the large imprint that moment left on your brain. I practice this with my own children now and even go so far as to occasionally put obstacles in their way to see how they fair. I help them through it as needed, of course, but I see how fast they can bounce back from diversion at times and I know I am improving their chance at survival.
In the end, we just have to have faith, that even if it doesn't work out, they will learn a valuable lesson in both life and cooking. It's worth the struggle, if you can possibly dare to attempt to look at it from their future's point of view. Through the struggle, something is born.......