I'm doing a fishing job for Devlin. The text of the fishing job is: "I've been told to pickpocket Alfhild Battle-Born's Flawless Diamond from Alfhild Battle-Born in Whiterun. I need to complete this job without killing the mark or getting caught and spending time in jail." Objective: "Retrive Alfhild Battle-Born's Flawless Diamond from Alfhild Battle-Born in Whiterun."

I sneak up on her to pickpocket the diamond and it is always at 0% (zero percent). I have tried boosting my stats with various apparel and potions, but it never goes up from 0%. I have also tried pickpocketing her at night when walking alone and when she is sleeping. The percentage is always zero and she always attacks. I don't want to fail the job, is there any way to reset this or will I have to wait for a patch?

I guess wait. You could pretend it is due to her amazing ability to see through your lack of skill.
Skulk away to vow to return on a day far far away.

Maybe some expert will know how to reset. Me no know.