Adding a 3rd dog??

I honestly wouldn't add another dog until your daughter is older.  GSD's are not an easy dog and with a small children.......

GSD's are incredibly smart.  They are self thinkers and able to function without human direction.  However, that often means that they make choices that don't make us very happy.  And, that can include eating furniture and all sorts of stuff that isn't considered good manners by us humans.  In my experience, a pup that young is NOT going to be overly tolerent of a child that young.  S/he will see the child as a littermate and those little high pitched screams will not do anything but encourage the pup to continue rough play.  And this is normal behavior for a pup of any breed, but especially so with a gsd.

No matter how much we love our critters, protecting our child has to come first, and a lot of happy, healthy, rambuctious pups end up right back in the shelter because of that one fact.  We can't expect children, especially children that young, to always follow the rules, not squeal, not run, not whatever, to keep the pup calm and there won't be much of a bond, ever, if they grow up on opposite sides of the baby gate.

I have 3 dogs and if I had my choice, I would go back down to 2. 3 dogs is just too difficult to manage at times. It is hard to make room in a car for 3 dogs + people or any type of travelling supplies/luggage. 3 is hard to go camping with (which I love to do). It is hard to walk 3 dogs at once. It is really expensive. They become a pack and do things they normally wouldn't on their own, etc etc. Life is just easier with 2 dogs.

 I won't tell you what to do since I'm about to get a third dog again, but three is definitely different than two.  It changes the whole dynamic.

Who evaluated Gabby?  Was the evaluation after Gabby killed your rat terrier?  You said that you felt Gabby was possibly responding to Sammy's behavior toward your daughter and that may have caused the aggression that led to Sammy's death.  This alone would make me very hesitant to add another dog, especially a puppy. 

The gender of the puppy would be the least of my concerns considering Gabby's past aggression.  Contact a veterinary behaviorist for an in home consultation.

As much as you want your daughter to bond with a puppy, I would wait until your daughter is old enough to be taught how to safely interact with the adult dogs in your home with a new puppy added to the mix. 

This article might be of interest to you especially if you're committed to acquiring a puppy.

http://drsophiayin.com/blog/entry/kids-and-dogs-how-kids-should-and-should-not-interact-with-dogs

Thank you for all for your input, to answer a few of the ?s that have been made.... Gabby was evaluated by a vet who specialized in dog aggression behavior, and she was found to be a very mellow dog and upon interviewing us for past history we realized that when Gabby was a puppy Sammy had attacked her in her crate, we had completely forgotten about that episode. Sammy had entered Gabby's crate wanting to "take over" the area and started a fight. I will take responsibility for not rehousing Gabby. And as gabby grew Sammy still pushed her buttons. Again I take full responsiblity. As for getting the third dog we are still going to go through with it. We have changed our minds on doing a GS, we are going to stick with the bullmastiff breed. We have always been a 3 dog home but now we have learned from this previous event and will take action immediately if anything should occur. I don't believe that a dog can't be forgiven, she has not showed any aggression toward any other dogs it was only Sammy.

I really wouldn't add any more dogs at this time. At the very least, a puppy require a lot of training and supervision, and with two dogs and a toddler, it may be daunting. Your daughter seems to have bonded with Gabby already so despite the lack of play, the bond can still be meaningful and teach her a life time love of dogs. As a kid, I had St. Bernard's and being able to have a furry shoulder to cry on was a great thing. I was also very bonded to my cat.

At the very least, a puppy will bite and scratch your daughter at least a few times. For some children, it's enough to make them fearful.

Walking three dogs isn't very fun. Dogs can get very expensive. If you are dealing with rescue puppies, then the chances of inherited disease go waaaaay up.

 

Do you have a plan worked out if Gabby should decide she doesn't like the puppy at some point? What if the puppy doesn't get it when she is trying to tell it to knock it off? It's your decision ultimately, but I wouldn't bring another dog into a home with a dog that had killed another dog, unless I really wanted to live my life crating and rotating for years should the dog show any signs of not liking the new one. I'm going to probably come off as rude, but if you're honest with anyone that she killed another dog, I don't know who would place one with you.

As for your daughter bonding with a puppy, she may or may not. A young kid is going to be too young to do the care required for the dog to really form a bond with it, and many young kids aren't huge fans of young puppies, who are mouthy, and obnoxious. My 21 month old niece has and excellent bond with Luke, who is 3.5. He is the only dog in our house who will fetch, and she loves to throw things for him. Luke is her pup, and it's been that way pretty much since she started walking. This is probably in large part due to the early socialization he had when he was still with his breeder, learning to deal with what tiny people can dish out. He can deal with anyone who will throw a ball for him. She has actually worked him in some activities (with help from me). He'll happily work for her, and probably will work for her alone when she is old enough to do it.

Getting a dog for a child is not what you are doing because the child will not have any direct responsibility. The dog is for YOU, because YOU want it. As an adult. I think this important to see...it is why we have gotten any dog. Because the ADULTS in the home...wanted it. Put the responsibility for adding the dog onto yourself because then if things do not work out? You will weigh the situation from the proper perspective...that of YOU making a choice that did not work out vs the dog "not being good with the kiddo" or anything like that. In your shoes I would not add another dog to ANY home where one dog has killed another. I would wait for the dog that did so was at the end of their time and gone. There is no way I would ever want to re-live that situation and regardless of what occurred or what a trainer says to me? I would have doubt and I would not put another dog at risk. Just me. Your mileage may vary.

I've never owned a bull mastiff, but.....that might be even worse breedwise.

My stepson was around 3 when he was nipped by a pup and to this day he is still afraid of dogs.  He's 32.