Regina knows that Dr. Hopper's Ph.D. comes from a curse, so she usually doesn't put much stock in the man's professional opinion. It's not the advice of a professional, but of a bug. But she's not stupid either, and there's a reason that she gave Dr. Hopper that Ph.D. He was genuinely good at his job, with or without the piece of paper to prove it. Yet sometimes she's still surprised when he manages to get something so… right.
Like telling her that her emptiness might be filled by being a mother – helping her realize exactly when that emptiness started.