Delphine is very much an adult before her time. But then she has to be, given that her mother, Cecile, has pretty much abdicated her parental responsibilities. By the time that Delphine and her sisters arrive in Oakland, big sister is already a mini-adult, taking care of her siblings as if she were their mother.
In carrying out the combined duties of a mother and big sister, Delphine finds that her Timex watch comes in pretty handy. It's no exaggeration to say that Delphine uses her watch to keep track of pretty much everything. In particular, she uses it to time her sisters' baths right down to the last second. This is all part of the girls' regimented bedtime routine, which, as one might expect, is run like a military operation. With her trusty Timex, Delphine is able to ensure that there are precisely twelve minutes of baths every evening before everyone hits the sack.
Delphine's Timex becomes almost like an extra limb. She finds that when there's nothing for her to do, it feels incredibly strange to have the watch ticking away with nothing for her to measure with it. Delphine's watch shows that she isn't just organized; she has a very rigid attitude to life.