Konami has released the November update for Metal Gear Solid 5: The Phantom Pain, details of which can be read on the game's website.
There are spoilers for the game below so you may want to stop reading at this point.
If you've played through the game you'll know that after Quiet leaves the Mother Base and can on longer accompany you during missions. The new update changes that, which is useful given that you'll likely have a lot of side ops and mission replays at that point in the game.
Following the update, you'll be able to bring her back into the fold by completing mission 11, 'Cloaked in Silence,' seven times. Once you've done that, the mission's name will change to '[Reunion] Cloaked in Silence' and Quiet will return to the Mother Base with all of her items and researched weapons.
There was already a PC mod that allowed users to bring Quiet back after she officially leaves the game but now console players have that option as well.