Without knowing the specifics, and no mention of nutes or additives it's impossible to tell.

Fill out the appropriate troubleshooting form, and you'll likely get a better diagnosis.

Something that shouldn't hurt either way, is a shot of molasses. (1 tsp per gallon) Has shitloads of micro's, magnesium, iorn, calcium...and shouldn't interfere with existing nutes in the soil. (which deplete after a couple/few weeks) Would think about resuming nutes at half-strength if you havn't already done so.

You said her leaves have been drying up and turning brown on the tips. Is this twords the base of the plants only?