"Papa is an odd duck." She would say she doesn't understand why her father would be drawn to him when they seemingly have nothing in common besides their daughter, but her best friend is a clever swot whose strategic mind is downright scary sometimes. She's always grateful it's never turned against her. Regardless, she definitely understands Poseidon.

You know, in the strictly platonic way that Jyn cares about Cassian.

Because they're friends.