Im not much use im afraid. It does seem to be a long time without much food - maybe phone your HV or NHS direct, they might be able to get you into the doctors to give your LO a quick check to make sure theres nothing wrong? Or even if they tell you to wait a little longer etc, at least you've got the ball rolling if you need to phone again later....although im probably just telling you what you've already thought of there....
Hope she starts eating for you!