Of course they know. It is confirmed by how others behave around them.
I have two sisters. One is 10 years younger than me, and very conventionally pretty. The other is not quite a year younger and achingly beautiful. I resemble my mother in a very plain/average way, and they were blessed with the lion’s share of my father’s genetic material. I grew up thinking that I was hideously ugly; look back at pics now and realize that I was a really cute kid, not to be mistaken for beautiful, but certainly not anywhere close to ugly. It was just that EVERYONE would fawn over Julie’s beauty, including aunts and uncles, and there wouldn’t even be an awkward pause when it came to me All were kind to me and clearly loved me, so they’re forgiven for being shitheads.
Julie knew that she was beautiful before we even entered grade school together. It was reflected in her unconscious acceptance of the feedback she got from the behaviors of people around us, and she learned very early to manipulate it to her advantage. As we grew up, we naturally became very competitive and resentful of each other. I hated how people – not just boys/men, but teachers, church members, Girl Scout leaders, other female peers – would fawn over and defer to her. Girls wanted to sit next to her at lunchtime. Boys would bring her cookies or run errands for her and fell all over themselves trying to get her attention. She accepted this as her due. When we grew into adulthood, she was completely inured to commanding “all eyes on deck” when she walked into a room. I felt not just invisible but hideous when comparing myself to her. And as unkind as she could be to me, I was a shithead to her as well. I took every opportunity to make her feel stupid, and like everyone around us, seriously underestimated her intellectual capacity and just assumed that I was in fact far smarter than her. She believed it too, reflected in the life choices that we made. I went off to college; she went to beauty school. We got close one summer when I stayed with her during summer break. And life knocked the arrogance right out of both of us anyway. Over the years I have come to realize that her beauty masked other fine attributes, such as her keen sense of humor, kindness, perception, and a very pragmatic intellect that surpasses my own. Given a scenario, I’m stuck with examining every angle, while she’s taken a snapshot assessment, made an inventory of choices, selected the best, and tweaked it to best outcome.
Our youngest sister is very pretty; not stunningly beautiful like Julie, but grew up enjoying many of the same advantages. Once, when I was in my late 30’s, we all got together, and youngest sister was late. When she arrived (with her then toddler and infant) she told us that she’d been running late, was speeding to make up lost time, and had been pulled over. She said that before the police officer made his way to the car, she unbuttoned her blouse and made ready with the “routine”. Only this time, the officer looked at her, glanced at her cleavage, looked at her kids, back at her, shook his head in disgust and wrote her TWO tickets: one for speeding, another for lacking a proper carseat for her son. Both sisters laughed, and Julie scolded her for trying the seduction routine with her kids in the backseat. She told her she should have went for “damsel in distress” instead: big, mournful eyes, a few tears for good measure, and a “my husband will be so upset.” I was floored by the whole exchange. To me, they may as well have been speaking a foreign language. It never would have occurred to me to even try to use my femininity in that way; I’d have just been extra courteous and cooperative and hope for the best (never worked). I hate men, just a little bit. And I love them too, because I’ve never been treated with that kind of "checkin’ big brain at the door’ deference. I ain’t beautiful. Men don’t lose their shit around me, and honestly… I think I got a better deal.