This week, she only grew a few centimeters in height and finally started to focus on the buds :). However, some leaves are not only yellowing, but also some spots have appeared. Still trying to figure out, what to do about that.
Day 54 update: after some other research, I believe nutrient burn could be the reason of my yellowing leaves, so I only did 1 plain watering with just a PH adjustment and will be reducing the nutrient amount by half.
Also did (hopefully) last small LST, some of the buds were already very close to the fan.