what are your temps? they look heat stressed. Your ph is a little low for soil too. 6.5 - 6.8
They also could be under watered. How often do you water?
50 - 100 ppm for 3 weeks into flower? She needs more food bro. I typically use 75 - 150ppm for early veg and 200 - 400 ppm in late veg. 650 - 700 for flower, not including any additives.
She's still got a little while to go. I don't count my flowering time from the moment I switch to 12/12. I start counting after the stretch. So figuring a 2-week stretch period, she's 5 weeks in to flowering. Another 3 weeks looks about right. Maybe 4
pics would help. Bottom leaves could be dying because of lack of light due to cfl's terrible light penetration. How many watts are you using? Side lighting? But most likely a PH issue. Rootbound plants will show signs of clawing as well.
I saw that too, that first pic looks a bit like a pollen sack. But as everyone else said it's still to early. Wait a bit longer and you'll know for sure
Are they actual watts or equivalent? And why does it have to be one or the other? I would use both. For an auto-flower, that should be sufficient for a decent harvest, but I would add some smaller cfls on the side for better light penetration.