Her behaviour towards my wife is completely different than with me

You’ve definitely put her under too much pressure, with some major inconsistencies between cause and effect that likely would’ve led to long-term issues. Despite that, you’ve managed to build a decent bond, since she’s clearly looking for your contact and attention.

Simply easing off that pressure and moving towards communication that actually makes sense to her—using simple cues that let her cooperate willingly—should make a massive difference to your relationship.

I think the main thing to keep in mind is that your dog needs to CHOOSE to cooperate whenever possible, rather than being forced into it.

To top it off, she comes from breeds that are particularly responsive! :-)

On another note, she’s an athletic crossbreed, all muscle, with a real need for constructive physical and mental outlets. If you let that pressure build up without giving her a way to "decompress", she won’t be in the right headspace to learn, and you can’t really blame her for that. Meeting a dog’s basic needs is a prerequisite before you can expect anything else from them.

If your wife can’t manage many walks during her pregnancy, she can focus on play and short training sessions. Learning about and understanding their environment is one of the most rewarding things a dog can do. When a dog gets into "mischief", it’s usually just them trying to burn off energy in their own way. By giving her a constructive way to use that energy, you’ll find the naughty behaviour disappears like magic. ^^

Your wife could set some daily goals to work on for a few minutes at a time. Guiding your dog and seeing her progress is a real morale booster!

On your end, make sure she meets as many other dogs as possible; it’s so important for any young dog, especially one that’ll have a jaw pressure of over 2,100 PSI (around 330 lbs per cm²) as an adult.

At first glance, it looks like it's off to a good start! ^^

A good dog is a reliable dog,

and a reliable dog is one that trusts its owner

and obviously understands what is expected of them

(provided these expectations are within their actual physical and intellectual capabilities).

Your wife can teach her how to stay calm and wait (at mealtimes).

The whole family needs to agree on and stick to certain rules.

These rules should be taught using rewards (play, food, and especially plenty of praise).

(The ‘alpha roll’ is like a symbolic death sentence. A dog would have to have committed an absolute crime to be subjected to that!)

When she’s alone with your wife, she pesters her to play. Play is an essential need for the healthy development of any young mammal,

and you MUST play with a young dog, but it’s up to the human to decide when, where, and how:

your wife should walk away and leave her for a couple of minutes when the dog starts pestering, but then come back with a toy and suggest a quick game of tug-of-war or something else the puppy will love. This will actually help her understand that humans won’t tolerate a certain level of overexcitement, as she’ll just be left all on her own the moment she crosses the line.

She shouldn’t try to go it alone with the training; it really is a family effort.

So the discussion isn’t pointless after all; I was wrong 🙏🏼.

Those methods did exist in the past, but they’re definitely out of fashion now... a dog’s place in the family has evolved. They aren’t kept outside anymore; they live in our homes. They aren't just there to guard the garden; they go for off-lead walks... and we no longer believe a dog is born aggressive or that they’re a "lost cause"...

Our expectations have changed, so the way we train them to get the results we want has evolved too.

I don’t think you have to be "purely positive" all the time either; there’s a happy medium. As a woman, I don't physically dominate my dogs. Instead, I use my temperament, my body language, and my persistence to get what I want. But this kind of training takes real commitment, so your wife really does need to get involved every day. This means things like giving the dog her dinner (calmly, after a "sit"), going for walks, and doing little 10-minute training sessions with treats and plenty of fuss, etc.

Basically what you’re already doing, but without the alpha rolls and that sort of thing 😉.

If we look at how a pack actually behaves (even though dogs aren't wild animals!), hierarchy isn't won through brute force. It's about competence: being able to provide food, security (the environment: shelter, protection from rivals...), and maintaining balance and peace within the group.

Stopping your son when he’s pestering the dog shows her that you can protect her and keep the peace. You’re earning your place as the leader, without using any violence 😉.

Beyond that, you need to observe the dog closely to read her behaviour. She might growl during play, or she might not; she might bark out of excitement or fear; she might nip to get attention or to test her strength... observation is key. It’s what helps you understand what’s going on in her head and tells you what to do to get the result you want.

It’s been mentioned already, but those times she peed while looking at you might have been out of fear rather than defiance. If you scold her, it’ll only make the problem worse if fear was the cause... which is why it's so important to understand the root of the behaviour.

The easiest thing would be for your wife to take charge of the food: she puts the bowl down, she hands out the treats (including giving them directly to the dog), she fills the water bowl...

I know it’s a bit old-fashioned—the wife in the kitchen and the husband out with the chainsaw 🤣—but it’s just so she can build a bond easily, especially since she might not feel comfortable doing other activities with the dog yet. When she’s on her own, there’s nothing stopping her from giving a treat when she tells the dog "on your bed" and she actually does it.