Excellent point, Wintertime
Her clothing choices are not suited to her body type, and definitely not to her role as First Lady,
Good tailoring can make someone look ten lbs thinner. So would chooses fabrics that are not shiny or clingy, and wearing the proper undergarments.
You can be sure even old Aunt Esther wore a girdle!
Since you seem to be an expert on this sort of thing, what about the length if her trousers compared to Carla Bruni-Sarkozy (standing next to her in the lavender coat with black trousers.)?
Michelle’s pant leg seems way too long and puddling like a curtain over her shoe, Carla’s is trim and just skims the heel. You would think Michelle’s needed a hemming.
Hemming would be the last thing to be fixed.
The crotch length of the slacks are too short and this is giving her a wedgie. Once this was adjusted, then I would adjust width across the hips. Immediately the pantie line, the wrinkles on the hips, back and thighs would disappear. Finally, I would adjust the hem to about the the length they are in the photo. The hem appears to be just skimming the top of her shoe.
The coat is too tight across the hips and therefore causing it to bunch and form wrinkles across the back. A gusset under the sleeves and kick pleats in the back would allow the jacket to lie more smoothly when raising the arms as she is doing in this photo.
Finally, the collar:
Is the collar supposed to be up or down? Make a decision and keep it that way.