I've never liked her writing at all - it gives the strong impression of being cobbled together in 25 mins and is often internally incoherent. She will say anything off the top of her head IMO and it doesn't surprise me she's not on the scientific side of this argument.
One side of the debate doesn’t think trans people are real; they might feel what they feel, but the rest of us don’t have to join them in that reality.
This is one of many untruths in that article that show a massive misunderstanding of the issue, failure to look into the facts, and willingness to lap up anything trans ideology teaches without questioning it.
If we wrote this sentence about, for example, Christians, it would instantly be clear that you can disagree with someone's unevidenced beliefs and feelings, while still respecting that they are entitled to have those beliefs and feelings, and of course that they exist.
"You don't think we exist/have a right to exist" is absolutely classic genderist projection and straw-manning but Williams lacks the critical thinking capacity to interrogate it.