She has a brother, Matthew, who is two years younger. In an interview, Kerr stated that her ancestry is mostly English, with smaller amounts of Scottish and French. She describes her early life in the Australian countryside as "very grounding You could just be you.
A study found that male fat admirers preferred females that were clinically overweight and rated both overweight and obese women more positively than slighter individuals. The study also found that participants reacted more positively to a much wider range of figures than a control group, even rating emaciated figures higher. It concludes "these findings suggest that an explanation for fat admiration may be that FAs are rejecting sociocultural norms of attractiveness". Full-figured or Rubenesque - the latter term referring to the art of Peter Paul Rubens , best known for portraying full-bodied women.