Wow, even after several years in Dubai it still strikes me how is acceptable to make sweeping statements based on someone's nationality.
Here's a suggestion. Check her references and see if her previous employers thought she was a good employee, instead of asking general questions about her nationality.
I pay my maid Overtime if she works on Thursday night ( after 7pm) or Friday (all day) I do it by the hour. I believe it is only fair, its her day off and I can't give her a day in lieu. She seems happy with the arrangment and is happy to work for us. Our maid has been with us for 3 years and she is happy and helpful.
I wouldn't appreciate it if my employer imposed upon my day-off without compensation so why expect anything different for your employee.