I'm not sure if this was covered but if it has, please accept my oversight. If not, please, read on! It is worth the time if you are curious as to whether or not you can tame more than one version of the model that is Uniquely Gara's!
I searched through the websites here and even elsewhere to find out if we would be able to tame Gara again if we "accidentally" released Gara after completing the quest to tame her in the first place. It was thought on other sites that this was possible but no one could tell me definitively if we could or not. So, I opened a ticket and asked a Blizzard GM. Their response was YES! But please read on so that there is no confusion.
The Blizzard GM I spoke to was very kind and patient and explained to me that it would be possible to tame an identical wolf by simply going back to the tree with the dagger in it and going back into the void. Once there, avoid attacking or getting too close to the Elder Void Lords and Elder Void Callers and make sure your track beast ability is on and just look around the area and you will eventually come across a Lost Netherwolf. It is IDENTICAL to the model of Gara and you can tame as many of these as you want to have in your stables! One thing to note here, however, is that this is a level 100 beast and to tame it, you would obviously need to be level 100.
I hope that this helps anyone that needs to re-tame the Gara that they may have lost during their adventures in Draenor and beyond.
I have attached several screenshots so that you can see that this is not something I made up.

This is me on my ALT Hunter, Laressa

Laressa with my UI, showing that she is level 93 and already has Gara but I wanted so show you that the Lost Netherwolf you see in the SS cannot be tamed until you are Level 100

This is my MAIN Hunter, Guinévéré back on November 16th when I originally tamed Gara at level 91.

This is Guinévéré at level 100, with Gara by her side and the Lost Netherwolf targeted.

Guinévéré without my UI, at level 100. Lost Netherwolf can be tamed at this level.
I hope that this was helpful to anyone that wanted to know this interesting bit of information.
Have a great day!
Laura AKA Guinévéré