The approach that my ICU preceptor used was to set reasonable, achievable short-term goals, and then help me to meet those goals. Once a particular goal had been reached, she would set the bar slightly higher--but still make it achievable.
One example: the first few times I got a set of Swan-Ganz numbers, it took me forever. Like, 20 or 25 minutes to remember to calibrate, get a wedge pressure, shoot a cardiac output, remember to turn all the stopcocks, do the calculations, etc. My preceptor observed this a couple of times and then said kindly, "Let's set a goal: within 4 weeks you'll be able to get a set of cardiac numbers within 10 minutes." Reasonable, achievable.
I first learned to suction a vented patient with another person bagging. Then my next goal was to learn to suction a vented patient alone. Then I learned to NT suction an unintubated patient with help. Then alone.
To be honest, 3rd Shift, the nurse "educator" you're describing sounds kinda lazy. Rather than do all the work of setting short-term goals and helping the LPN achieve them, she's simply saying, "Here's where I want you to end up. I don't care how you get there, and don't expect any help from me, just get there." I agree with you that her methods sound counterproductive. One would think that she could see by now that her methods aren't necessarily working, at least with this particular new grad, and could manage to be a little more flexible.