Like many other predators, dogs roll in strong smelling substances to disguise their scent. It's not likely that she can be trained not to do this. However, you might be able to curb the behavior a little by providing her with a more pleasant scent -- a little perfume, rubbed into her fur. Use common sense, of course, in applying it -- don't get it near her eyes, mouth, nose or genitals, or use so much that she'd get sick from ingesting it if she licks it off.
You can buy perfumes designed especially for dogs with odor issues, but it's not really necessary, so long as you take common sense precautions with what you apply.
This is not a guaranteed fix, but it helps in some cases.