Hi ilikthtbet!
I am glad that the Rottweiler Mastiff mix found a home and your wife can handle her so well.
Generally speaking, fearful dogs can do better with women. Men's voices are deeper and their bodies are bigger so those dogs have more fear towards men.
Also, I don't know much about the breed Rottweiler and Mastiff except for they are both recognized as being protective, not friendly to strangers. Since you and your wife adopted her only Friday so I bet you are still a stranger to her.
You didn't mention how old the dog is but if she is a puppy it will be easier for her to get used to you. If she is a full grown then you might want to reconsider adopting her. You might want to learn about those breeds first. They are not kinds of breeds that can be friendly with anybody like a Golden Retriever or a Lab. Usually pounds don't let those dogs get adopted by families not familiar with those breeds so you and your wife might be familiar with the breed. If so, please ignore my comments.
Since your wife managed to get through the dog's fear, I assume she has experience treating and taking care of dogs. When you are afraid of dogs, they will quickly feel some uncertainty and act either to be aggressive or to be fearful. In contrary, if you approach dogs naturally, they tend to accept you better. But it is all depend on each dog's personality so I don't know if it works for your dog or not.
I really hope your dog is still a puppy. If so, he will have a plenty of room to get socialized from now on.
In any case, it has been only a couple of days and you said you had been hand feeding her so my suggestions are:
1) If the dog is an adult dog and you and your wife don't have much experience with raising dogs, return the dog and get another (more friendly) breed. Otherwise, both you, humans and the dog will be unhappy, and the worst case a third person if the dog bites someone.
2) If the dog is a puppy (up to 4-5 months), study about the breed and take puppy training classes (hopefully both you and your wife participate together). Keep hand feeding her whenever possible. Take advantage of all the occasions you and your dog can be together alone without your wife. Also take every opportunity for your puppy to get socialized; towards other dogs, other humans, all kinds of noises, smells, etc. that we human beings take for granted.
3) If you and your wife adopted the dog because you both like those breeds, I assume you are more familiar with the breeds than me so please ignore my comments.
I personally don't believe in Alpha Techniques so I don't recommend them but it might be beneficial to correct some behaviors. I strongly believe that dog-human relationship is not the one based on dominance but with understanding and trust in each other.
I with you and your dog the best!
