What JW wishes for children (freedom to explore and change their minds) is great, but I fear she'll be leapt on for showing she doesn't know the actual state of play:
“Where I would be very, very worried is young children taking any kind of drugs, hormones or whatever, the long-term effects of which we don’t know. And the whole idea of having major surgery… if you’re a young child it’s not a question of just having bits of you lopped off. It’s really serious, difficult surgery, which can have pretty devastating consequences, I would imagine. It’s nothing to be taken lightly.
The NHS doesn't prescribe puberty blockers to "young children" and surgery is not allowed till 18, legal adulthood. "I would imagine" is not a solid basis for a high-profile writer to make a statement about a contentious issue.
She has jumped into shark-infested waters without inflating her old-school life jacket. I loved her books and she's been a force for good in getting children's issues out there in public over her long career, so I wish her luck on this one.