This is so incredibly sad and so very telling.

When Regina’s mother utters words to her that she has longed to hear all her life, she can’t even assure her mother that she is happy. Regina isn’t happy.

But she indicates she can become happy if they find Hook. Because Emma believes that will make her happy. And for Regina to be happy, Emma has to be happy.

That’s where Regina’s guilt and feelings of obligation to Emma come into play. Emma sacrificed herself, and then Hook died, for Regina’s happiness, and Regina isn’t happy. She can’t tell her mother that she is happy. 

But she knows she can be the closest thing to happy. If only Emma gets to be too.