Just wanted to update, after switching to 12/12, she greatly improved. The yellowing abated and now she's looking great and green and has begun budding. I only switched up a few things, notably setting up a larger tent to allow better heat diffusion and removal and to allow me to keep my lamp at an appropriate distance from canopy (about 23-25"; LEDs). She made rapid improvement after flipping to 12/12 and bloom nutes, so I'm wondering if it was some deficiency after all, coupled with the possibility that they were growing too close to the lamp.
Either way, as it stands, we're smooth sailing right now, just over two weeks into flower. They're sleeping right now, else I'd add pictures, but I just wanted to thank every body for their time and assistance in helping me to remedy the situation!