I am so sorry for you and your entire family, Anna. Malone will heal, but it'll take time. When I lost my childhood dog that Graham knew for many years, it was a very hard mourning period, but eventually Graham healed. I even thought he enjoyed becoming an only dog before I decided to adopt Kersey. He was happy as an only dog after the mourning period passed.
I know it's harder with a little baby, but I did a lot of stuff for Graham that helped after his companion of many years died. I took him to the dog park frequentlly, to the lake to swim and chase the ducks, and on car rides. All these things he enjoyed and it kind of took the edge off of the grief for the both of us. When my heart-dog Graham died, I had Boone to heal Kersey's broken heart, so it wasn't the same situation as going from 2 to 1 dogs.
I wish there was something I could do or say to help you threw this. It's an absolutely horrible thing to go threw. Unfortunately, there's nothing that helps excpet time, time and happy memories. You, Mark and Malone are in my thoughts and prayers. I am so very sorry :(