I don't believe she has any way of knowing your actual current salary. In that scenario, I'd simply say a current salary within 15% to 25% of my new salary expectations. Moreover, your expected salary is something you should be aware of from your own market research. Some professions early on in your career may require some guess work. You need to say a number you're happy with. I've said a number 10 to 15% higher many times. If they are interested in you as a candidate, they will work with you.