I didn’t learn it b’nogeah to hilchos Yichud. I will have to look that up when I have a chance. But we did learn about the concept.
In any case, I don’t understand something. Even if נשים דעתן קלות, wouldn’t that be counteracted by the fact that men have a bigger yetzer hara? And what about the fact that there are more boys at-risk than girls?
And I don’t see what the Bruriah story proves since there was also a man involved.