You really think so? Because i dont even think the old friend part does fit. She was his lover, mistress, aunt, his brothers wife, part of the family and abuser of him. Nothing of that i would really take equal to a old friend.
Well, i have a theory, but it is really just from my own experience about how stuff like this can happen in stories you are working on and that have become so big that it became easy to overlook such small details. And that is that the "old friend whos name starts with a T" is an old reference to niki, when the name he planned to give her started with a T, only that he changed her name to Niki later, and just forgot that he had implemented this reference to an old friend who's name starts with a T.
But it is really just speculation, so take it with a grain of salt.