you can change money here. travellers cheques, whatever it's up to her. i'm not sure how much money you can bring in to the country in cash, i'm not well travelled myself (only been O/S once) so i'm not up on these things. i think travellers cheques are regarded as safer or less easily stolen and used.
i think overseas calls are cheap, when i look at the rates they're cheaper than interstate calls here. it would depend on her provider though I spose. you can buy phone cards here (at newsagents and supermarkets and lots of other places) and use public phones, i think that's very cheap and it's geared towards travellers. i know a lot of them use these cards. they would sell them at the airport and the calling rates are on the back of the card or something.
summer is very hot here!