Hermione took in a sharp intake of breath when she saw Ron holding Lizzie. It was the first time she could ever remember seeing him holding a baby. It looked... really good. Really right. And Hermione was fighting that maternal instinct again, the desire to procreate with him. She wanted him to be holding their baby daughter.
It caught her by so much surprise that she took a moment, staring at him, to collect herself. She was speechless.