Remember people aren't allowed to discriminate against you when you are pregnant, even if you are casual/temp. People are not allowed to ask you questions about your family situation eg 'are you married', 'do you plan to have children' because those questions are not relevant to the job or work tasks. So, really she shouldn't be asking you how far along and how big you are - she should be stating the physical demands of the position and only asking if you will be able to meet those demands. You are well within your rights to refuse to answer personal questions like those. Maybe next time she asks them, ask her what physical demands/limitations there are in this role - so then you can say whether you are able to meet those or not. End of story!