Thanks. That's what I thought, but then there are other forums which says your 18 months period start at the last entry , not on the first entry. In any case, here is the maths as per your earlier posts.
Between '07th Nov 2017' AND '14th June 2018', she stayed 219 days
Between '11th Sept 2018' AND today (i.e. 03rd Jan 2019), she stayed for 114 days.
219 + 114 = 333 days in total until today. 365 - 333 = 32 days left.
Today (I.e. 03rd Jan 2019 ) + 32 days = 04th Feb 2019. Which means, she can stay in Australia until 04th Feb 2018. Is this correct calculation?