While Paul is a real jerk, Victor, Félicité's poor nephew, is another story. He visits his aunt regularly and brings her presents from his sailing trips. He is, for her, like the son she never had. When he quits writing letters it is actually only because he has died, which unsurprisingly breaks her heart.
There's not that much information about Victor as a person in the story, but it's the role he plays that's important: he's someone who's related to Félicité, who belongs to her. She doesn't have to share him with Madame Aubain like she does Virginie.