the closest place to jumbo with african elephants, as we all know is dubbo. its also a good zoo, with lots of space. logic dictates that would be the be the ideal.
another equally ideal scenario, though it may (or may not) be easier, is for her to end up at another african elephant-keeping zoo of equal standard overseas.
if she can't be offered that then you would have to settle for asians as company. this is not usually something i'm too fond of, but plenty of zoos have examples of mixed-species elephant bonding. surely its better than being alone.
in that case i would like auckland to take her. they obviously are never going to breed their asians and i'm sure their resident elephants wouldn't mind the company.
but really, what would be the benifit of bringing this animal to australia if she was not to have company? she may as well remain in NZ as far as i'm concered.