The problem is she never wants to join in with the others - when they are swimming, she doesnt want to do it. When they played hide and seek, she did kinda refuse to participate and when they stripped, she didnt want to do it and with the sexual positions (well, understandable!)
She just needs to start getting more involved with the group as a whole else she will be seen as an outsider.
I noticed this is mentioned on interactive, the producers are noticing it too I see.