That's my thing too, we, as shooters, constantly talk center mass, and that applies to animals too.
I don't advocate or push shots like this on anyone. If the opportunity and confidence of the shot was not there nor the absolute 1000% knowledge that the bullet would have gone exactly where I wanted it, then I would have shot her in the high shoulder. I don't attempt shots like this very often and never without a full rest and "bone bridge" built to make everything rock steady. This was a rare occasion that presented itself to me and I took full advantage of it. I've also worked with this gun and load through hundreds of rounds of practice and knew without a doubt that the bullet would enter right behind her eye into bone.
I'm an experienced shooter and hunter that doesn't get rattled or nervous when a deer comes out that I want to take. Now, bucks with large bones on their noggin's make me excited but I generally take them within a 1/2" or less of where I was aiming.
This really wasn't a very long shot for me, in fact, I'd have been a little more leary of it had she been say 50yds since I would have had to take into account the angle, rise and other factors.