I felt she was trying to look at my genitals, attempting to determine my gender
Again with the genital obsession and projecting it onto others.
I'm 45 years old, I started working with the public aged 14. I must have met thousands upon thousands of people over the years and in all that time never once have I felt the need to see an adult someone's genitals in order to ascertain their sex, no matter how they were dressed.
It might be difficult to tell in small children, but adults? Even kids approaching puberty? Nope. Dead easy. No one was looking at your genitals, mate. No one needs to. We can all tell your sex from your face, hands, shoulders, hips, walk, talk, smell.