spotty yellowing of veins on leaves. started at th...

She may have root damage ... or she could have a zinc deficiency or both... calcium/magnesium is ruled out here as this is starting at the top of the plant, not the bottom .... I would tend to think it more likely her roots were damaged by something - perhaps overwatering but I'm only guessing. My advice is to make absolutely certain you keep your pH where it is, and that she dries out thoroughly between waterings/feedings. Plants will all react a little differently to the same set of conditions/treatment and this one may not be drinking as fast as her sister.... Just a guess here - I've not seen that before! Good luck!