Rather than quote one of your comments I'll give an answer that covers both. I believe her intellectual capacity is...fine? What I have noticed is that students coming out of both high school and college are not taught how to think critcally anymore. There is also a big difference between concrete and abstract thinking. The last time I saw a study on this, 55%? of the population does not possess the ability to think abstractedly, again because they are never taught the skill. Neither a lack of critical thinking nor abstract thinking points directly towards stupidity, just poor education.
As an aside, I think her comments are, on occasion, very clever.