Looks like over fertilizing issues. Encoupled with a possible ph imbalance. Every plant,strain,pheno has different needs. Those needs can change as well among clones in different environments. I'd give her a good ph balanced watering to 6.3... using no nutrients or additives. That damage wont mend or get better. Just watch to see no more occurrence in new leaves. When picking back up the feed dial it back from where u last were.