I just want to say it seems like your misinterpreting the whole "she looks like a boy" thing
Anyone who looks at her up close can tell that she is a girl but she specifically chose to cut her hair and wear mens' clothes so that she'd be in less danger of freaks chasing her skirts (not to disguise herself and actually trick others into thinking she's a boy, just make her look less like a piece of ass cuz she'd already recently be threatened with r.pe and being branded as a sex slave)
From a distance, she looks like a boy and that's how the majority of people who don't see her up close see her (which are the ones spreading rumors)
Also, cutting her hair didn't make her look completely different, but it did make her less noticable. If she still had well cared for "princess length" hair, it would catch unwanted attention
She cut her hair to make her less of something to look at and it worked and they basically forgot they even made a princess into a slave (she wasn't important enough to kill and wasn't important enough for a second thought)
This isn't necessarily to convince you or anything, basically the story didn't immerse you enough to enable your suspension of disbelief and that's fine ig
This story seriously pisses me off. I'm at chapter 36 and I'm stopping there. It's so unrealistic. Firstly all she did was fucking cut her hair, and now apparently she's a totally different person that they can't recognize at all?? Fucking stupid. Secondly SHE DOESN'T EVEN LOOK LIKE A BOY. AT ALL. Honestly it's very very fucking dumb. She looks nothing like a boy. But I guess "Woman has short hair? Must be boy haha " dumb. dumb as hell. LIKE OMG and what is this stupid ass plot of them thinking he's gay??? Like it's just... Stupid. And boring.