Have you been reducing their nutes already?
I haven't grown Blue Widow, but have grown White Widow & lots of other Widow crosses.
The leaves look like they only have about a week to 10 days left but I would of thought the buds would be a little fuller at this stage. I think I would of fed nutes for another week or two, then flushed 'em.
Have you run this strain before?
If so, then I'll assume you know what's best for it.
If this is a first run, maybe next time let it go another week or two.
Regardless everything looks good.