Here's an excerpt from The Guardian about the matter.
"Her legal team told the high court last month that the clinic’s approach was unlawful because the potential risks of treatment were not adequately explained and that children could not give informed consent for this kind of treatment. The case could have serious implications for the issue."
No one, regardless of age or competency, could possibly give "informed consent" for life-changing treatment if the potential risks are "not adequately explained".
The fact that the Tavistock treats under-18s means that extra care must be taken.
Who in their right mind could argue against the need to ensure that potential risks are adequately explained and that consent is truly informed consent?
That's what Keira Bell is asking the court to consider.