Do not apply for the History of Economic Thoughts. Or you can apply for now
if your philosophy background helps. But it has very small demand in the
market. Even she wants to target teaching.
My suggestion, find her interest in Economics without compromising for her
philosophy degree/background. That's specilization all about. Believe me,
you got too much to learn in any Economics field. For making a living on it,
you do not want to spread out even before you start it.