Here is how I usually bring her back.
First you play up to the point just before you enter the mage fight sequence. While Amie is still alive I save the game under quicksave plus two other savegame entries (sounds like overkill I know, but it can make a difference).
Continue playing the game until Daeghun sends you to retrieve the shard. Once you are in the swamp with Bevil quicksave the game and exit.
From Windows copy the 0_amie.ros and Roster.rst from one of the other two savegame folders to the quicksave folder. You will need to confirm to overwrite Roster.rst - 0_amie.ros was already deleted by the game. Now that these two files have been replaced at the quicksave folder, relaunch the game and load the quicksave game.
Use the console givexp command to readjust Amie’s experience points to match yours. Now, VERY IMPORTANT, save the game to a new savegame entry. After that quicksave should work fine.
I have neglected to create the new savegame in the past just to have the game crash when I tried to save and delete my savegame folder.
This procedure will need to be repeated at two other points in the game:
After the Vigil at Solace Glade and After the combat with Lorne.
Probably just need to copy the the Roster.rst file at those two points in the game. 0_amie.ros should still be there.
You will need to be a little bit careful and understanding with her. She was really shaken up by her experience at West Harbor. If she get knocked unconscious, she can lose all of her gear.
I can usually recover her gear if I pick it up before she regains consciousness. Otherwise it tends to fall through an extra-planar portal. You can see where it went, but you cannot get to it. This only happens once or twice though (assuming she gets knocked unconscious).
She is worth it though. She also sticks really close and insists on going on every mission with me. Her security blanket I suppose as I was the one who resurrected her. But I would not have it any other way.
She is loyal and gentle and good-natured, and extremely competent.
This is an RPG after all, so play along ;).
A couple other tips. Apparently the Roster.rst file save experience points for other companions when they are not active in the party. At later points in the game I use gr_dm to make all current companions active just briefly so their ros files can be updated. It makes the process of updating experience points easier after the Vigil and Lorne. I would avoid bringing in companions you have not encountered yet, might cause problems later.