For the moment, Lily was all business when it came to dealing with Dumbledore at least in regards to magical plants. Of course she smiled back at him.
"Good morning to you, as well." She waved off his concerns about disturbing her. "Yes, it is. We've had good luck with the current crop." She gently cupped one of the leaves. Lily had developed a fondness for the various species of plants she was now working with. It helped that she often came to the greenhouses when she wanted some alone time.
"You're not interrupting," she mentioned. "That's what I'm here for, magical plant related things." Lily didn't mind when he got closer, finding his stance and demeanor unthreatening even with the way his eyes focused on her face. While it was a little odd for Lily, she was genuinely trying not to blame people for what their future selves had done. Even in relation to her family and how it affected Harry. If her son could let bygones be bygones, then Lily could strive to do the same.