Mavis, as the tactician she was, of course had something in mind when she asked for this meeting. She knew those days in the woods outside of Magnolia had been happy ones for Zeref. So if anything was likely to sway him and make him reconsider his project of awakening E.N.D. and dying - and maybe killing everyone else in the process - that was probably it.

So yes, one of the reasons why she did that was for the greater good. But the other reason was that those days had been happy ones for her. Over the last century she had often missed the company of the wizard that she'd gotten to know back then. The one who taught her magic and helped her become the powerful being she was. They were both more human back then. And she craved experiencing that feeling again.

She didn't try to be quiet as she approached him. Quite the opposite in fact, she used an illusion so that he would hear the sound of bare feet on the grass coming towards him. She knew him well enough: even with his eyes closed, he was still very much aware of his surroundings. Mavis' only regret was not to actually be able to feel the cool grass against her skin as she could back then.