You're allowed to feel uncomfortable but let's not spread misinformation. It's notchanging sex, it's changing gender which is a social construct and therefore malleable and changeable. The doctor, if they're a reputable one, is not looking to justify anything and much less making such basic assessments as "girl=likes dress". They're assessing and evaluating whether there is a true gender dysphoria or whether it might be something else. I don't know how reputable the doctor the SJs are taking E2 is, and there are indeed quacks out there. Hopefully they're the real deal and will go beyond "oh likes Barbies, must be a girl." It's a process that takes months, even years.
Also, let's not equate grooming with telling a child that if they do X they'll get Y. I'm not a parent but I've seen literally all parents I know do this. "If you stay quiet while Mummy talks on the phone, I'll give you an ice lolly after," "if you're good, Santa will bring you presents," "if you get good grades, you can invite your friends over for a sleepover." The SJs are awful parents, but in this regard, they're the same as all. Coercion seems a staple of parenting.