My WWidow plant's buds are not really fatteni...

Hello ! That dark green colour is a sign of nitrogen excess on a late stage. You don't check your EC/Ppm level so it will be hard to really know how much you nutrients you gave her since the start but I can see the excess settled between week 3 & 4 and you were using a 8-5-5 npk nutrients , if you did not respect the cycle water / nutrients / water / nutrients etc then it could be the cause of your issue , in the other hand if you did respect that chart then maybe you should go with a water / water / nutrient / water / water etc .. schedule . When you started your 10-16-25 NPK nutrient then you plant should have changed a bit her colour so your plants are under nitrogene toxicity and it is why their are slowly flowering. I guess that your flush did not wash enough nutrients away , maybe just wash the salt buildup but still remain plenty of N in your soil , so if your molasse is just a PK nutrient then use it until the colour become a bit more pale , if not then maybe another flush will be necessary to "reboot" your soil and then restart with your 10-16-25 nutrient. I hope it will help you and I encourage you to get an ec/ppm pen as soon as possible to avoid any nutrients excess/deficiency 😁👍