The child is allowed to choose their own name, pronouns, hairstyle, and clothes. They periodically check in with a psychologist to find out whether this still feels like coming home, or whether it’s last week’s craze.
That’s it. That’s all they do at such a young age. Nobody is doing anything irreversible at nine years old because of course they aren’t because duh. Doctors aren’t stupid. They know that these simple changes make trans children very much happier and greatly reduce the risk of self-harm and suicide, while still leaving the door open to remaining cis.