[@SouffleGirl123] [@Sisyphus] I figured Billie is staying at the same shabby apartment complex as Emily and Alan, so they have probably met  more than one occasion. Billie would try and be cordial around Alan whenever they meet. She'd at least admire and get drawn to Emily's fun reckless personality which I guess  fits in a way with Billie's carefree /fuck it way of thinking.