It used to be, back in the dark ages when I went to school, that girls were not encouraged in the STEM fields. This has definitely improved as women have pushed their way into many places once deemed inappropriate or impossible for women, and they proved their worth. There are very few teachers left today who have the bias that only males can excel in math, science and technology. The sciences, especially, have many more women than 50 years ago. Technology, not so much, yet.
I disagree that the schools are inherently sexist. No more than the underlying sexist biases of our culture generally.
So you have particular examples?
If you look at the test scores you still see that girls are behind. They may not be open about it but there are teachers that consciously or unconsciously steer girls away from the sciences. I
Your claim has no concrete empirical evidence, therefore it must first be assumed as correction inclined delusion (which has no fault or guilt involved and must therefore be kindly addressed and appropriately reformed by actual concrete empirical evidence). I am not writing this as a scientist, but as a teacher.
Read your own words.
"Look at the test scores, see that girls are behind."
There is nothing concretely empirical about that claim. If the test scores are indeed in the form of sheets, and we indeed look at the scores within the sheets we should first be able to pay full attention to it without paying attention to whatever is physically, concretely, empirically behind. Even if we had the ability to look at the scores within the sheets and still pay equal attention to what is behind, the probability is that immediately behind there would be the hand holding the sheet or a desk of some material or another, never forgetting about the sheets themselves and the scores.
As soon as you mention there is anything unconscious about science or any teacher whatsoever you lose the capacity to absorb and effectively learn the topics to be studied in their own appropriate way to be fully comprehended and cooperated with.
The material world, rocks and cement included, also have to be cooperated with, and are not in our realities only to cooperate with us for other aspects within our realities, although they do in fact cooperate. So must you and everyone cooperate with yourself and everyone else. That's how the world works, only by first understanding the world can anyone first engage in actual science.
Scientific and educational access are free and have always been.