Red Dawn : Rewatching and question about sisters

Who was supposed to been older? It looks like Grey's character but near ending she acted more timid than the other.

Also I get the guys knew the girls dad & perhaps saw them as sisters. But is that the reasoning for no romance between one of them?

Could have been cousins, I think Ben Johnson simply referred to them as granddaughters.

I think Toni was older than Erica. As to the romance, there was actually supposed to be a romance between Jed and Toni (yeah, I know, Dirty Dancing, shut up) but it was cut, according to the trivia section. Also, when you are fighting in a war, you aren't exactly interested in *beep* There was also the crush Erica had on Capt. Andy, remember? And maybe in the end, when the two survivors make it to freedom, Erica and Danny, they could've ended up getting married later on.