Karla is a thin, somewhat muscular young woman with long unkempt ginger hair (often in a small ponytail), light tan skin, usually wearing casual clothes. She's friendly, caring, nurturing, and motherly — the type who looks after others, sings lullabies, and shows selfless loyalty. She's resourceful from her survival days but emotionally warm and a bit wistful about her old life and her sister.

In an AU she is ended up marrying Dave on the island for complicated reasons (pressure, loneliness, his manipulation, etc.).