Avoiding the bug
About the Forsworn Conspiracy quest:
Followers may get permanently stuck in the Shrine of Talos,
regardless of if the quest is completed and you escaped from Cidhna
Mine. If this happens, the follower will not leave even after you tell
them to go home, and if they are moved elsewhere via console, they
will walk back to the Shrine of Talos, no matter where in Skyrim they
are.
From: UESP Wiki, "The Forsworn Conspiracy - Bugs"
I'd recommend not having a follower while doing this quest to avoid them getting stuck in the Shrine of Talos. Or you could ask them to wait outside the Shrine. Multiple backup saves are also recommended.
Fixing the bug
If you've already encountered the bug and can't load a previous save, try these*:
Try the enable and disable console commands.
Make a save game first, and then in the game, open up the console by pressing ~, then click on your follower (in OP's case, Aela). Aela's RefID (0001A697) should show up in the screen. If the RefID is correct (meaning you have selected Aela correctly, and not another object), type disable and then enable in the console. This should 'reset' her.
If Aela is not near your location, you can still select her by entering the console command prid 1A697, after that type disable and then enable. Then try the moveto player command (which moves that prid-targetted entity near the vicinity of the player) and see if she gets 'reset' and decides to stop her pilgrimage to the Shrine of Talos.
If it still doesn't work, try finishing the Forsworn Conspiracy quest and the next quest that it will trigger, No One Escapes Cidhna Mine. See if your follower will now follow you.
(I know OP has already posted a solution that worked for them. Just posting alternative solutions in case someone else experiences a similar issue.)
With help from cyrus224 at Nexus Forums:
Walk up to Hert and press the ~ key at the top left of your keyboard to open the Console.
Click her, then type the commands listed below.
Or you can copy and paste the code into Notepad.
Scripts must be in the same folder as TESV.exe
C:\Program Files (x86)\Steam\SteamApps\common\skyrim
To execute a script type the following command into the Console:
BAT scriptname
where scriptname = the name of the script file
Example: Bat VampireCureHert
How to Cure a Player or NPC with Vampirism
Choose a RaceCode. Don't execute this command if you want them to continue looking like a Vampire (or you could execute this code just to change how Hert appears and NOT cure her).
SetRace NordRace
Then you need to run all of this code, which is why it is suggested to do it in Notepad.
AddToFaction 000C4DE0 -1
AddToFaction 0002EB13 -1
AddToFaction 00046281 -1
AddToFaction 00027242 -1
RemovePerk 0010F1EC
RemovePerk 000F5B56
RemovePerk 000CF02C
RemoveSpell 000F5B54
RemoveSpell 000ED0AA
RemoveSpell 00107AA1
RemoveSpell 000F5B58
RemoveSpell 000F5B59
RemoveSpell 000F5B5A
RemoveSpell 000F5B5B
RemoveSpell 0008D5C3
RemoveSpell 0008D5C7
RemoveSpell 000ED0A9
RemoveSpell 00088821
RemoveSpell 000ED097
RemoveSpell 0010F1E7
RemoveSpell 000ED0A8
RemoveSpell 0002E1C3
RemoveSpell 000ED099
RemoveSpell 000ED09D
RemoveSpell 000ED09E
RemoveSpell 0010FB30
RemoveSpell 000F5B5C
RemoveSpell 000EA077
RemoveSpell 000EA078
RemoveSpell 000EA079
RemoveSpell 000EA07A
RemoveSpell 000EA07B
RemoveSpell 000C4DE2
RemoveSpell 000ED0A4
RemoveSpell 000ED0A5
RemoveSpell 000ED0A6
RemoveSpell 000ED0A7
RemoveSpell 000C4DE1
RemoveSpell 0008D5BF
RemoveSpell 0008D5C0
RemoveSpell 0008D5C1
RemoveSpell 0008D5C2
RemoveSpell 000ED0A1
RemoveSpell 000ED0A0
RemoveSpell 000ED0A2
RemoveSpell 000ED0A3
RemoveSpell 0010F1EB
RemoveSpell 0010F1EA
RemoveSpell 0010F1E9
RemoveSpell 0010F1E8
RemoveSpell 000F5B5D
RemoveSpell 000C1E8B
RemoveSpell 000ED09A
RemoveSpell 000ED09B
RemoveSpell 000ED09C
RemoveSpell 000B8780
Best Answer
Never mind. I just traveled to Solstheim it’s southwest of the temple of Miraak.