I'm using the unbreakable weapons mod if that changes anything.
Hey there, I'm the guy who made the unbreakable weapons mod. I don't
think it should be causing any issues, as small as it is, but I can take a look and make sure it's on-par with the latest release of the game. (The only thing that might create any issues involves the file getting replaced in a patch, but even that shouldn't theoretically break the game this far.)
In the meantime, using a text editor, open up and look at the save file: are there multiple entries of Gavrielle? If so, there's part of your problem; you're going to want to delete the duplicate entries. If not, you can open look at and remove items from her inventory. All information relating to an item is delimited by a double bar. ( || ) Deleting a strip of information from between these will remove that item from her inventory; for example:
<Inv>Practice Sword,Weapon Hand,c:Swordsman:Fencer:Hero:Champion,,,Sword,15,25,0,0,0,0,0,0,-1,0,0,0,0,0,0,0,0,0,0,0,0,20,0,10,,Sword Wooden,Flimsy practice sword. Strength -1.||Bandages,triggered,,,,,2,16,12,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,20,,Bandages,Restores 12 health.</Inv>
If I wanted to remove the practice sword from this character's inventory, I'd delete this:
Practice Sword,Weapon Hand,c:Swordsman:Fencer:Hero:Champion,,,Sword,15,25,0,0,0,0,0,0,-1,0,0,0,0,0,0,0,0,0,0,0,0,20,0,10,,Sword Wooden,Flimsy practice sword. Strength -1.||
which would leave me with just
<Inv>Bandages,triggered,,,,,2,16,12,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,20,,Bandages,Restores 12 health.</Inv>
If that doesn't help with your problem until Craig can swoop in and prevent it from happening again, I don't understand things as well as I thought I did.