I just have to say I love the names for the Rosier girls. BEA & DEE (and Isabelle should have a nickname along those veins too)! Also, yes, I have the UP TO DATE family chart for the Rosiers. So many cousins, omg.
ANYWAY. Evan is of course her cousin! Also the undisputed baby of the generation and very much the spare. I think he likes Dee very much because why wouldn't he? Well, and she's family, but it's better when your family is likable because then you don't have to actually make the active effort, etc.
Emmeline is probably too young to know her! Know of her, probably, and be vaguely acquainted through the same social circles?