Hmmm, freckles!

You've got the bare beginnings of a calcium - MAYBE a potassium deficiency probably caused by a little too much nitrogen since your pH is spot on. You can certainly flush if you feel the need but I don't think the problem is that bad... you might just want to give her plain water for a week instead. At this stage in the flowering, she's not needing as much nitrogen so I would remove your BioGrow entirely for at least a week a or so... at LEAST cut it in half for the rest of the grow. You don't have to cut your other nutes down and you may want to add a good PK booster, get those buds fatter and rock hard... Looks good otherwise - good luck!