Ready to harvest?

Looks too young to me. I've done 3 White Widow harvests, and these look young. I'd also look into the cupping leaves. Something is stressing this plant. I agree that a magnifier scope is a necessary tool for any grower. Only $15 or so but you need at least 40x to inspect them. I harvest when 33% of trichomes are dark.

Looks ready from what you can see on the pics but the one true way to tell is with a min of 40x microscope I prefer 60x, relatively cheap to check the trichomes with you want mostly cloudy for energetic or around 10% amber for more relaxed but autos can flower for longer than 4 weeks, I've got a green gelato auto that has been in flower for going on 8 weeks and is in final phase of flush, hope this helps 👍