Agree with Manitas, I doubt it was a 'blonde' inability to comprehend something extremely obvious, but a mental block moment. I've done it myself!

"Then there's this response, by a woman who tells folks to lay off making fun of this poor woman, and explains why it wasn't fair to expect her to be able to answer this question"

YouTubers seem to have missed that she's playing up a stereotype, very well too. I expect she gets a laugh from the volume of genuinely stupid feedback 'ridiculing' her.