I told you -- he's like family. [Though, compared to some of her "family" that Firo is aware of...]

The good family, that is. He's trustworthy enough that he's willing to overlook the differences he has with people. That we don't always see things the same way, and he doesn't try to force that to change.

[It helps, not being preached at. Rey knows full well what kind of person she is and doesn't need someone to try and "fix" her.]