My personal experience going to a school in that field (now 20 years ago), back then, there were practically no girls there. Our school had 5 years, and in the first year, of 5 classes, only 2 had any girls at all. By the end, I think of the 2 classes finishing, there were only a handful girls in about 50-60 people. So I think it is still no wonder there are so few female engineers around.
I honestly don't know why so few girls choose a tech career. At least where I live, there is nothing preventing them from doing it. The only thing I could imagine is the "social norm" or peer pressure from their friends in middle school, to just choose a more social or non-tech school later on.
This is still the reason I don't really talk about my gaming hobbies with a lot of people, though I know I should not be ashamed of it, especially nowadays.