Not sure on waiting times, changnoi. Probably picking up this time of year as well as the Embassy's warning that processing times will increase due to Olympics applications.
One must expect to wait for up to three-months and anything less is a bonus.
You really should look on the bright side. Your wife will apply on Thursday and that will be that until she has news of a decision. It took over nine-weeks for my wife to receive her decision eighteen-months ago. She takes her LITUK test next month and applies for ILR in October. All this stress will be a distant memory in next to no time.
This really is no time to be skulking about and definitely a good time to prepare for the arrival of your wife. I'm sure there's a million and one things you can be doing now.