could be maybe. Those girls still seem to be early in flowering however they could be just building bud too. If you got heat issues id say its more likely although too much nitrogen can elongate the buds as well (been there before too cause i didn't switch nutes earlier like i should have) so ya i would start with determining if its a heat issue but i honestly don't see any other signs of heat stress but you just need to give it a little time and observe your girl cause she could just be getting ready to bulk up. Sorry that i can't give a definitive answer but you didn't provide enough information. Good vibes your way!
Well foxtailing can happen for many reasons besides heat. As for flowering before mature i think you should look at some journals of 12/12 from seed cause ive done it and many others as well and i didn't end up with foxtailing From that.
Nothing wrong with foxtailing if it packs on more buds. I had foxtailing when I let my OGKs go longer than they should have been harvested. I finally just called a halt to the process and harvested them. About 100 days in flower! my family thought it was really good smoke!