If you aren't trans you're not going to have any interest in transition.
How can you be so naive?
Does the knowledge of homosexuality make you want to have sex with men?
That's armchair science. This is an empirical question; but it's one that's very difficult to get reliable data on. There are any number of anecdotal reports from parents that their adolescent daughters showed no sign of being trans until one of the other girls in their cliques decided she was a boy, and then the first trans child's friends started deciding they were too. But of course the "social contagion" hypothesis and the "me-too movement" hypothesis are both consistent with the parents' observation, and there's no obvious way to tease them apart: "Extraordinary popular delusions and the madness of crowds" is a real phenomenon; but closeted children keeping secrets from their parents until a friend gives them the courage to come out is a real phenomenon too. So when a group of girls come down with so-called "Rapid onset gender dysphoria" together, what actually happened? Progressives will inevitably argue that their parents were oblivious to signs that the girls were dysphoric all along, or else they deliberately hid it from their parents, while conservatives will inevitably argue that it's because children are easily influenced by their peer group's notions of what's cool. But the truth is surely sometimes it's one, and sometimes it's the other. People are all individuals.
There are a number of answers to the "me too" phenomena and most of them involve a fairly standard process: discussion with professionals who have seen exactly this phenomena before. Those professionals have a great many sessions with those who claim they are trans and then within 2-4 months start blockers and put their puberty on hold, try actuating on what they say they feel, and then usually give up because it's a lot of work to pretend something like that when it isn't really who they are.
...Just like there are some people who decide they like hats and wear hats for a month or two, and then there are people who really like hats and will punch your lights out and kick you in the head if you try to take their hat off their head.
The point of blockers, one of the things this law bans, is to allow kids to actually think about it for longer, so that the permanent and immediately oncoming changes to their body as a result of these decisions are not made lightly, or on impulse, because this, unlike a hat, is a decision that if made lightly and allowed to go too far, is very costly and painful and only imperfectly repairable.
Of course, it is equally costly, painful, and imperfectly repairable if ANY mistakes on direction are made, even mistakes caused by allowing the biological default.
Currently, the balance is on "way too many expensive defaults".
Once again we can discover who speaks in bad faith by looking at what people talk about around the issue: one side is clearly calling to ban blockers, and then defends this call by talking about preventing cutting, despite blockers preventing cutting; the other side talks about blockers: safe, reliable, works as advertised, causes no significant permanent changes when used as advertised for short term puberty prevention.
Obviously, education could help greatly on the matter but recent laws addressing sex ed are banning teaching LGBT issues.
How do you tell the difference? You fucking talk to them, take everyone seriously, give them the time to figure themselves out, and let them access the medications that allow that.
Humans grow and develop mentally to adulthood (those who ever do...) without needing a sexualizing puberty at all. The puberty part can happen any time before 30, really, and with education on hormones and their effects given the knowledge that ultimately, the choice is up to the taker, they will form their own strong opinions on what they want in a time before social cliquing encourages mimicry.
The scary part is to those who are dead set on grandkids, and the idea that they may not get that in the way they envision. Anything to prevent that fate, right? That's what people really fear: difficult children who don't give the parents what they want out of the relationship. Problem is, expecting things like that out of relationships is the core driver of abuse.