Has your wife been to the BW before?
If she has not been on a trip her imagination might make her worry more than if she has taken a trip herself.
If your wife has not been camping much with you get her out in the woods for a day or two.  Show her that you DO know what you are doing.  If she is confident in your skills it might make her feel better.

If you end up meeting up with others sell her on the saftey net of others being close by and looking out for each other.

One thing my wife liked was going over the maps together.  I took one of the planning maps like the outfitters give you and marked where I planned to be on each day and the area I planned to camp.  I also gave her the number for the outfitter and the Sherrifs office.  She seemed more comfortable knowing where I would be on what day.  Instead of just me going "up there".

One other thing I did was to ask my wife exactly what she was worried about and then deal with each worry she had.
After my solo my wife said she was never really worried just missed not seeing me for a week.  I did get her blessing for future solos as well.

Good luck,
Beavers