Jessica & Jennifer are twin sisters, though you would have trouble telling. Since Jennifer is not only taller but mature looking at age 13, even though Jessica being older by a few minutes she looks like the littler sister. Despite this, the sister are super close and care for each other deeply. Jessica even comforts Jennifer her when she's upset. Also, because of Jennifer looker older than she's supposed to, it can lead to them doing stuff that other 13 year old can't do.