Shallow end of the gene pool, Cookies has been overbreed and passed around so much it's a genetic mess, then you got Pollen chucking peeps that cross something Durban with something kush and Wham! ....New Cookies....
Had a discussion with a few breeders years back or so and the basis on the conversation was most of todays cookies was typically unstable, very finicky, and prone to Herm. Each time iv run something with a stated cookie line it's been a hassle, typically find balls mid flower or a few surprise seeds deep in the bottom of the jar(bucket), mostly the plants were "special needs" plants and at the very least P.I.T.A
remember lots of Strains have been sent overseas, breed with European genetics, then backbreed or recreated to a close substitution and shipped back to you or said Pollen chucker,
Not like you hear peeps talking Thin Mints line (west coast Clone only right!) Just GSC or Cookies but from where? Who's cut?
Actually got a Ethos End Game mother with Collins cookie line in it ATM and it the same story, didnt like being cut, tied down, moved, looked at, hard to cloned, hated variations to the water but man.....kicks my head in kinda smoke so much I'm keeping it alive to run again for the deciding if the challenge is worth the reward.
Best I got for yah is manganese from iron toxicity (you got well water?) She's is a sensitive girl to minor changes, maybe try lowering her Ph a little but you'll probably fight this one till the end.