Hmm, so maybe shapeshifting is a part of her physiology and she'd only learned to control it later on. But she's still mostly human, aside from those animal influences and something curiously compartmentalized in a way the TARDIS can't see it without intruding. It may be interesting to learn more about Daine, but that's not really relevant to the matter she's currently trying to solve, so she is content to settle for 'different universe' as an explanation.

"I should begin my search for Morpheus while it is still nighttime," she announces thoughtfully. "Thank you for your help. And I have to ask you not to mention my presence to anyone; if those organizations - Romac and the rebels - become aware of me, they will try to exploit my abilities."