Mira isn't in my party & I did edit itemcreatemira.2da while I was editing itemcreate.2da
EDIT: I think I see my problem; I had my items set as heavy armors but their upgradelevel was set as armored robes.
I guess that one small detail can make all the difference.
EDIT II: Oops. My problem was the plot; I set to it to a number other than 0. After setting it to 0, my problem was fixed.