Will, I think Guest Zoe means the octave G string on her 12 string.
I use Elixir light guage on both my 12 strings and have had no trouble for the past 4 or 5 years APART FROM THE OCTAVE G! (only a couple of times) To be fair, it's ceilidh band playing and is fairly rhythmic, so the octave is vulnerable (in my hands anyway). Having said that, I find Elixirs to be far and away the best for 12 string playing.