58 year old female gets plenty of exercise and eats a clean, correct diet but is gaining so much upper body weight. Why?

Need fewer calories. Anything that uses energy (calories) will help one lose weight, as long as she does not eat or drink back more calories after the activity. Examples: if walking, take a longer route; use stairs instead of elevators; park a block from school and walk there with the kids; at home, skip dessert and go walk around the block instead. Doctor can check to be sure weight gain is not water, tumor, etc...