What am I missing?

Context.

In a formal social context — i.e. 13 year old performs at a piano recital — we'd say "young woman/lady" to elevate and show respect for their effort.

In a familiar social context, I might call that same kid "twerp" because she stole my clicky pen to stim with.

In a criminal context, we're talking about agency.

Young women (18+) can be independent, have a job, make decisions about their lives. They have enough agency to say yes to having sex with an older man.

Children (<18) can't give informed consent like that, which makes sex with an older man automatically sexual abuse.

The press is being accused of implying that the victims (children who did not have the agency to give consent) belong to a category that can consent to sex with old men (young women) in a context (criminal) where agency matters.

What? No? Maybe colloquially, a mother might say "young lady" to her daughter, but that doesn't mean she thinks her daughter is an adult.