Jumping back to the two messages from late August, which I must have missed somehow:
With respect to the question asked by Drummond, who apparently has not visited the board since posting his message, the Ismays had no connection with the Isle of Lewis that I'm aware of; as to Aberdeen White Star, I don't know.
Inger, your question raises an interesting possibility. As you know, the vast majority of my material is North Atlantic oriented; I have very little on White Star's Australian and New Zealand services. What I have, however, says that Gothic served on the White Star/Shaw Savill joint service from 1893 to 1907. She then served Red Star as Gothland from 1908 to 1911, but was, as you mentioned, returned to (I thought) White Star for about two years' service to Australia and New Zealand, 1911-13. Note, though, the title on the following postcard, which I believe dates from this period, and which I had simply written off as a mistake until reading your message:
As noted earlier in this thread, White Star effectively controlled Shaw Savill, and together they controlled Aberdeen White Star. Moreover, although it's kind of tough to tell from this image, the funnel color and flags shown on this card don't look much like White Star's. It may well be, then, that when she returned to the White Star family in 1911, Gothic was operated by Aberdeen White Star rather than by White Star or Shaw Savill and that the caption on the card is not simply an error.
There's nothing more I can add based on the New York-oriented materials I have immediately available to me, but the next time I take a peek at The Times, I'll see what its shipping columns might have to say about this.