Calcium deficiency. Copper rust spots are a text book case of calcium deficiency. They will never go away, which is fine, but you can prevent it from spreading. When a deficiency hits fan leaves, it tells us it is a "Mobile Nutrient." The plant needs more of this nute, so she is taking the nutes from her fan's and putting it into her new growth. This tells us it can only be one of a few nutrient deficiencies. Matching the spots with mobile nutrients leads us to calcium deficiencies.
Add your correct amount of CalMag and pH it to 6.5. And continue this throughout your grow.
Calcium absorbs pretty well at this level, without raising your pH too high. All will be well. Don't remove these leaves. She'll be just fine.