I must admit, Xs and Os always confuse me .... so the stops are in MEL and BNE? If so, why fly MEL-CNS-MEL-BNE? Or is it the other way round and the stops are CNS and MEL?

If it's the latter, to avoid BNE being a stopover, it may have to be last flight in/first flight out. We had that recently on a OW Circle SWP/Asia ticket where we were going MEL-SYD-NRT. Would have much preferred to take a late afternoon flight to Sydney, taken the train into town, had a nice dinner, train back to the airport etc and then out the next morning to NRT - couldn't do it because we weren't allowed a stopover in SYD and so it had to be last flight of the day in/out the next morning (on the first available flight).

As for AA or QF SYD-SFO, not sure it makes a difference - if she's going to be in the QF program, might as well pick the QF flight number.

As for who to get to ticket it, not sure you can get AA to do it as they no longer have an Oz ticket office, since they closed North Sydney. If you find a way to get AA to ticket it in Oz, let me know as I have that problem. You may have to get QF to do it ...

.... though now that I think about it, I guess any AA office (well, almost any) could do it. The ticket has to be issued in the country of origin (Oz) to get the Oz price; if ticketed elsewhere, that country's price applies, but only if it's higher. A and D tickets are more expensive out of the U.S., the U.K. and Oz than they are out of say Japan. We start our DONE4s in Japan and have AA Tokyo issue them. I guess there's nothing to stop AA Tokyo issuing the ticket and charging you the higher of the Japan/Oz price (which will be Oz), which is what she would be paying anyway. If it's electronic (=< 16 segments), they should be able to do it by phone/email. I had them do 3 tickets for me last week, so can provide details, if needed.