Character Analysis
Luciente is the future.
And yeah, she's got some individual characteristics, too. Over the course of the book you learn that she's "not quick witted" but "thinks through things… carefully" (10.254). You learn that she's willing to fight in a war, but not willing to hunt animals. You learn that she gets all breathless and flustered when Diana shows up, and that she loves her daughters.
Person as Future
But in a lot of respects, Luciente is used to explain, and symbolize, the difference between the past and the future. For example, one of the most striking things about her is that she "spoke, she moved with the air of brisk unselfconscious authority Connie associated with men" (3.67). In fact, Connie mistakes her for a man at first. But this isn't a characteristic of Luciente herself, in particular. It's a fact about the future—all women there aren't treated as lesser people, and so have more confidence.
Person As Author
Similarly, a lot of Luciente's dialogue in the book is devoted to explaining how the future works. That's her job, both according to Mattapoisett and according to the novel. She's a plot device as much as a person—a way to tell Connie what the future is like without just having Marge Piercy show up herself in the novel, typing away at her computer, covered in cats. (Piercy loved cats.)
It's perhaps not an accident that Luciente loves gardening and cats as Piercy does. The character is a way for Piercy to tell Connie things Connie couldn't know, or wouldn't think of. It's a useful tip for you if you want to write a novel: if you need to help your character along, just send them someone from the future to tell them which way to go… and give them your own likes and dislikes.
Luciente's Timeline