Going to grandma's house always means flowery scents, good cooking, and fun family time, and that's what you get with Lily's Nan, May. Or almost, anyway. Lily describes her as "a picture-book granny, except for one thing: she had an imaginary companion […] a made-up friend called Sef who accompanied her most places" (1.7). While we've all had imaginary friends, most elderly women don't have them unless they're senile. May, though, is far from that.
May grew up in an orphanage, which is where she met the real Sef, an older girl who served as her protector—until Sef was suddenly adopted, and left before May could say goodbye. So sad. And perhaps because there wasn't any resolution for her with Sef as a girl, May continues to keep Sef around for company, if only in her imagination.
On the upside, May's rough childhood has made her a better mother and grandmother than she might have been otherwise. Not having a family as a child helped her understand the value of one, which is why her husband's quarrel with Lonnie and Marigold's failed marriage hurt so much. "They were such a small family," she thinks to herself. "They couldn't afford to let any single one of them get lost. And getting lost was easy" (25.6). Yup—family super matters to May.
In a way, Lily and her Nan share the common goal of reuniting the family, but they definitely have different methods of doing it. While Lily bosses her mother and Lonnie around and orders them to fix situations, May quietly observes her family and seems to sense what they need. She has a whimsical attitude toward this seemingly impossible task, planning a "celebration" (7.74) for Pop's birthday as a means of bringing everyone together. And you know what? It works: May pulls the reunion off. Big time.
Don't think that Nan's entirely a sweet little old lady, though—you don't want to mess with this granny. When people don't take the necessary steps to solve a problem, she's more than willing to take them on their behalf. Check out the part where she throws the ax Pop threatened Lonnie with into a ravine. With the symbolic weapon gone, in her mind, they are free to have "a perfect, cloudless day" (25.28). May may be whimsical with her party plans and imaginary friend, but she rolls her sleeves up in the real world to make her dreams into reality.