After sneaking into the men's loo, Lily returned to their table feeling incredibly relaxed. While James composed himself, she took a walk around the bar, saying hello to an old school chum, returned herself, and then she just had to give her granddaughter a little hug before letting Harry's other family return to their meal.
When she returned to their table next to the boys', James still wasn't back so she caught Harry's eye and kicked the seat out next to her. When he took the hint and came over, Lily looked smug as she kissed her son on the cheek. "About time. Thought you were going to pretend we didn't exist forever."