Yellowing bottom leaves lack of nitrogen?

Yes your lady is a bit low on nitrogen,nitrogen is a mobile nutrient so if the the soil gets low on nitrogen the plant starts to pull it from the bottom leafs(she does with all mobile nutrients) If your plant is showing signs at the top your problem is a deficiency or lockout from immobile nutrients So with your next watering add some grownutrients and she’s back on track.the yellowing leafs don’t turn green again You can take these off when your sure here nitrogen level is back on track,if you do it after another leaf will start yellowing And Try to feed or water your plant like madeingermany said is the best way to prevent problems ✌️Happy growing and stay safe 🌱