Why did Caroline move into a new apartment building before April arrived?

Caroline is
April's grandmother. When April lived with her mother, she had visited her grandmother in a
different apartment--a one-bedroom apartment. When April comes to stay with Caroline because her
mother, Dorothea, is "on tour," Caroline has moved into a different apartment
building, the Casa Rosada. It is a rather old-fashioned building, which to April is much more
appealing than the "tiny supermodern apartment" Caroline had lived in before. The
reason Caroline moved is so that April could have her own bedroom. This perturbs April because
she doesn't think she'll be staying long enough with Caroline to need a room of her own. April's
mother had told her she'd only be staying with her grandmother "for a little while."
The fact that Caroline moved to a larger apartment in order to accommodate April foreshadows
that April will be staying there longer than Dorothea has told her daughter, which turns out to
be the case. Readers understand that Dorothea had probably told Caroline something different
than she told April. This foreshadows to readers that Dorothea is not honest with April and
doesn't really want to have April back with her anytime soon.