My only advice is big breakfasts and snacks all morning. If she has a good hour or two in the morning that's the time to try to get some cals into her. Unless you are going the no-dairy route i'd be putting butter on toast, cream in porridge, giving her bits of cheese to snack on through the day... You can also get booster drinks in most supermarkets (not sure which brands you have in Aus) which are worth a go if she's finding eating hard going.

Poor kid, i hope she's on the mend soon...

Bx