Not getting option to upgrade to Safari 6.1
I have a couple older Macs around the house that are running on Mountain Lion and unfortunately can't be upgraded beyond that. One of them, a MacBook Pro, got the option to update to Safari 6.1 among other things. The other is a Mac Mini. Even though that's on the exact same OS, same version, I don't get an option to update to Safari 6.1.
I tried to use Google to find a place, hopefully from Apple.com, to download Safari 6.1 but I did not find one. Is there anywhere I can find a place to download Safari 6.1? Even if not, is there a way to fix it so that the Software Update option allows me the option to download Safari 6.1? As I mentioned I have no clue why it won't present me with this option.
Thank you in advance.