Two of my girls are taking long to flower and have...

Hi @PapaSmurf416! Nitrogen plays an important role in your plant's health: this type of yellowing usually means that your plant is not able to find enough Nitrogen. Too much Nitrogen = dark leaves, stunted flowers, big stretch. Not enough Nitrogen = yellow leaves, lack of vertical stretch, bottom leaves dying. Your slight Nitrogen deficiency is related to the plant doing its "stretch" cycle. Once your plant enters into flowering stage, she focuses on vertical stretching for a few days, before putting all its energy into bud expanding and resin production later. In your situation, I won't worry that much, the stretch should be over now and your plant is going to need less N and more P+K. What's your soil and what's your feeding schedule? Depending on those elements, you will probably need to add some P+K into your next waterings, to help flowers to expand. Hope this will help, keep us updated and happy growing! 👊