We've got a female lab (fixed) that just turned one year old earlier this month. All-in-all she's been a very loving member of the family that also includes a one year old male (fixed) we got from a rescue organization about three months ago. And, the two dogs get along just great. However, the lab for many months has been nipping at my wife for attention, or when she gets scolded, which naturally scares my wife.

And, I think the dog knows it as up until the other day she's never done this to me. But, just the other day when I tried to put her outside she almost took a bite at me. I had initially called her to get up from her bed and when she didn't make a move I grabbed her by the collar and that's when she almost bit me.

After this occurred, it's got me very concerned about what to do. Like a lot of folks, we have various visitors and some have small children. Any suggestions on how to correct this behavior would be greatly appreciated. Thanks.
All the best...JB
If these people ever had more than one dog, they just might know something about Alphas. At any rate, they seem to be having fun selling snake oil and used bridges to the unsuspecting..or to people who like to make a big deal out of nothing.
But why not get on with the show and simply remind the dog where he belongs, next after you!
If these people ever had more than one dog, they just might know something about Alphas.

I think that a large majority of the regular participants here have multiple dogs. I've got four from a breed that cares a great deal about pack structure (Siberian Huskies) and I think that you're giving dangerous advice that could get the person who made the mistake of listening to you bitten.

Melinda Shore - Software longa, hardware brevis - (Email Removed)

The image is Adam Smith. The reality is Enron Joseph Stiglitz
If these people ever had more than one dog, they just might know something about Alphas. At any rate, they ... snake oil and used bridges to the unsuspecting..or to people who like to make a big deal out of nothing.

Which people are you talking about? We're about as diverse a group of dog owners as you'll find anywhere.
You're sounding a bit like a religious fanatic who has one answer for everything, regardless of the question. The OP has set up a problem situation, rewarding mouthiness from a mouthy breed, being inconsistent, encouraging protest biting, and allowing the wife to become and show fear of the dogs. Telling them that life will be simple if they just read Koehler is just simply no help at all to them. It's as meaningless at this point in their problem as Jerry Howe telling them to read his ridiculous manual!
I'd recommend that they call the rescue they got the male lab from, admit that they need help, and describe the problem. Any decent breed rescue I know would have someone at their door within 24 hours to help them set up a basic management routine and household rules. They need to get those things well in hand, and then get into a good obedience training class.
Lynn K.