Regina promises she won't push Henry to remember her, to love her again. So she kisses his forehead and exits the diner leaving Henry behind, again. Tears stream down her face as she's just barely half way across the street when she hears it, what she's longed to hear for so long.
"Mama!" Henry cries out and runs towards her launching himself into her arms.
"Oh, Henry, Henry, my little boy, I love you so much!" Regina cries grasping tighter to the boy.
"I remember, I remember everything," he smiles, tears pricking his eyes,"Don't ever make me forget you ever again, I love you!"
"I promise Henry, I promise I'll never let you go again."
There she's found it, the other part of her heart. Emma watches having witnessed the exchange of hugs and declarations of love between Henry and Regina, she just smiles.
And Regina smiles back, "I'm never letting either of you go again."