Lily had no idea that Al was only here because of her. She noticed him hanging back from the crowd, making a mental note to ask him about it later. She could hardly blame him, knowing from experience that memorial services could be depressing, draining affairs. Still, it was polite to attend these things, even if one wasn't fully certain who the person it was for was. It would have surprised Lily to learn that Albus felt as though he couldn't say no to her, since that seemed ridiculous to her. She wanted her grandchildren to feel comfortable enough around her to be honest and speak freely. Not to be scared of somehow disappointing her.
She shared her condolences, giving James a quick hug before slipping out of the crowd to meet up with Albus. She got the impression that he was doing his best to fade into the background, and would respect that. She had no issues with letting Albus pick where they spoke, as this was about getting to know him.