I'm not quite sure if every single one of The Others are associated to someone in the main house, but which pairings are looking likely in your opinion? We already know that Ryan & Sam and Charlie & Jason have some sort of past.
I think...
Andrew & Evelyn: I feel these two know each other in some way. I did think that they were related at one point but it's quite unrealistic.
Hughie & ???: I really have no idea with this one
Jayne or Natalie & Chelsea: I think either one of the females knowing or having some sort of romantic relationship with Chelsea is possible.