Elsa's next appointment is two days before Christmas. She hasn't gotten Anna a present yet, so she suggests going out for lunch afterwards as a treat. It isn't really all that much, and Elsa certainly doesn't think it's a good replacement for an actual, proper gift.
But then Anna asks, in a small voice, "Like... a date?" and Elsa realises that she's thinking about this all wrong. That she isn't thinking about Anna, or what she'd like for Christmas.
Anna, the girl whose greatest desire... is someone who loves her.
A family.