They go out to dinner a few nights later. It's a celebration, and Anna has a bit of extra cash because living with Elsa is cheaper.
Elsa tries to pay but Anna refuses, and if she's honest with herself, it's really nice. It's not- it's not a date, but like. Going out somewhere nice, with a friend. Elsa hasn't done that in ages; can't even remember the last time Hans took her anywhere.
It's warm and perfect, and Elsa realises that, despite their differences... in Anna, she's found a lifelong friend.