I've lived in Wagga, it gets very hot, I dont think giving you the option to fit A/C or she'll move to a house that has it is too unreasonable, thats what I'd do in that situation.
I'd go a swampy over a split system, the install costs may be dearer but the swampy will better cool the whole house and maintence should be cheaper as swampys are much less complicated that a split system. Swampys are pretty much just a water pump, a fan and a float bowl similar to whats in a toilet.