Well she looks one of the most genuinely happiest people I have seen in the press for a long time. Kate and William seem very happy together too.
Do I think she has an eating disorder, she looks like she is underweight for her height, and not getting in enough calories for the amount she is burning off. Anyone who doesn't eat enough fuel for the amount they burn off or eats too much and doesn't burn it off has an eating disorder. If she has an eating disorder, then that is something for her to address.
If someone has an eating disorder, then it is no one else's business, you asked for opinions so this is mine.
Kates under intake of calories looks like it has been going on her whole life if the pictures of her as a child are anything to go by, she was painfully thin looking in that picture of her in a brownie uniform as a little girl.
I have seen a similar incidence of Victoria Beckhams son, he is a very lean child as she was and still is, the other two boys are quite average sized and the middle one is very thin.
I would say Kate is fit, athletic no, she has defined muscles which are small as she is so lean, her muscles are no bigger than anyone else's would appear if they didn't have that 20% of fat covering their limbs that is considered healthy. Kate looks like she is underweight for her height, and will not be getting in enough calories for the amount she is burning off.
I also don't think Kate has a very femimine figure, she has very wide shoulders, and no hips, so instead of the desired hour glass she has a male inverted triangle figure.
I do like Kate, she seems a jolly lady, a perfectionist, well meaning, she presents herself very well both in behaviour and in the way she dresses and I wish her well. Kate is a human being doing the best she can and I for one would not ask any more of her.