Why is it significant that Félicité sleeps in her chair in front of the fire?

Félicité sleeps in her chair instead of in a bed. A bed is a place of sleep and rest, while a chair is usually a place where someone is resting, but awake. That Félicité sleeps in a chair instead of a bed seems to suggest that she is always ready on some level to begin working. She never fully rests, but instead sits up at night in case she's needed. Sitting all night in a chair is also how a person stands watch. Perhaps the image is meant to invoke Félicité as the guardian of the household.