Vina's "no guide" statement was way out of kilter with the fact that the Talosians themselves were humanoids, by the time the script was cast and filmed.And, yes, I took Vina's comments as accurate too. I don't see a reason to see her as misleading. The Talosians knew enough and that's about it.
In-universe it's clear that, like so many surgical patients, Vina came away with a poor understanding of what went wrong. And the Talosian doctors weren't about to wise her up, because it was their own post-technological incompetence that wrecked her. Of course they would prevaricate and be evasive. And then they sent her to the Zoo, where she was "patched up" with illusions.