I am considerably larger than the DoC although i have friends who are a similar size and some who are larger.. I think she is a very attractive woman.
Things i think she does/has that currently i dont:
Motivation and discipline - although i think i would be considerably more motivated if my photo was going to be circulated the world wide and scrutinised - just as i am more careful before a big event like a wedding. Her life is full of big events/public appearances whereas mine is not. Even my supersized ego couldn't deal with the criticism she gets.
Flexibility - between work, school runs, keeping on top of diy/gardening/food shopping i am quite time poor. I imagine she has more flexibility in her days some weeks. I am not good at prioritising myself but thats ok - my work role only asks that i am clean and presentable - her role demands an expectation (rightly or wrongly) of how she appears.
Height and body type - she is tall and lean and i am short (atleast 5 inches shorter) and portly. Thats just the genetics we get given. Cant change that, its the cards we are dealt with.
Stress - just different stresses. I suspect she probably doesnt worry about how to pay next terms swimming bill or the mortgage or who is picking the kids up but then i dont have to worry about my children's security or what the media might print about me or my family.
I think its a combination of being careful, genetic makeup, access and time to exercise and a dose of hardwork and motivation. Of my slim friends some work very hard at it, some don't have to whereas I have to work hard at not getting fatter.