She didn't answer, because she couldn't focus on this thoughts under the water like she was. It didn't occur to her that she couldn't breathe, that she didn't need to. It was a warm, comforting, cotton-wrapped thing, and her mind and memory went blank as she floated there; lost moments.
The voice in her head didn't try to ask to come out, though it very much wanted to. See, the mermaid wanted to be on land, not under the waves. Being in a bathtub would hardly give her that, and she wanted the girl to feel better; she didn't want her to die. So the mermaid stayed quiet, and Anya didn't answer, and the water ran over the edge of the tub in the steam-filled bathroom.