Thinking skills-new info

I am currently teaching art to a young woman who had a stroke. (I did not know till now that teen could have a stroke)  One of the requirements for teaching this gal and others like her in the future is talking a 3 day course on brain function and anatomy-sigh my brain hurts now!  Anyway I found out today that higher level thinking skills do not fully develop until 18 to 21 years of age. (myelinazation of the axons of the frontal lobe- is the term) This includes the ability to problem solve, imagine future consequences, plan for future events,  make judgments, and reflect on events and behaviors. While it was stated that it is  very important to stimulate young minds to encourage neurons to grow and become stronger we must always be aware that we need to be aware of  how we present "thinking skills".  While some students will be able to model this ability at a young age because of exposure it is "modeling".  Just as we do not expect an infant to get up and run, we can not expect children to have higher function thinking skills.  We need to model and show students how to think through problems. No argument there. But asking students to "think" through new situations will be setting them up for failure.  The example is that you speak to an infant above their speaking skills and so we model "thinking skills" knowing that one day they will be able to apply it and be able to "think" for themselves. (hopefully anyway unless things like traumatic brain injuries)