While Hermione likes to think of herself as a mature adult, the fact of the matter is that she'd been repressed for so much of her life that talking about anything that even tangentially has to do with procreation would still leave her stammering foolishly. It's best to avoid that sort of talk altogether.

After a moment of silent pondering, she asks, "Is it muscle memory, then? Because that seems a bit questionable when, if I'm understanding you correctly, a new body would mean entirely new muscles."