Why is it significant that Joanna eats in the kitchen in The Adventures of Huckleberry Finn?

The setting of chapter 26 in Mark Twain’s
Huckleberry Finn is the home of the Wilks family during a dinner
where Huck and the impostors who called themselves “the duke” and “the king” were
guests. Huck ate in the kitchen with Joanna, who was the youngest of the sisters. He
noted that she had a cleft lip, for which he nicknamed her “the hare lip girl”. Although
the narrative does not indicate anything strange about Huck and Joanna eating in the
kitchen what could be significant is that:

a)      Huck and
Joanna were the youngest diners. The special places at the table were often reserved for
adult guests by order of precedence.

b)      The family was
embarrassed to have a child with a visible facial flaw, hence sent her off to eat in the
kitchen alone. However, this is unlikely because the sisters treated Joanna quite
lovingly.

c)       The family wanted the younger diners to
get acquainted, so they separated them from the elder
diners.

d)      It was a good technique to add to the story
because, from this acquaintance, Huck developed affection for the Wilks that motivated
him to protect the sisters from the con men.