Elsa doesn't push for details. She just holds her friend.
Eventually Anna does speak. The tears have stopped, but she still sniffles a little. In a way, it's also cathartic. She's never told anyone before.
"I was... twelve. Olaf was four. I thought he'd- people don't want a twelve-year-old to take care of. Too much work. Too much hassle. I told them to split us up. I wan- wanted to give him a chance, y'know?"
Elsa nods, though with a sinking heart, she has an idea of where this story is going.