There are many ways to light then. A good thing about an Interview is you can really perfect your lighting. Its all a matter of your personal taste. I would suggest a large soft source to the side as key. I often like to bounce light off of some bead board, foam core, what have you making that the light source then sending that through a frame of diffusion in other words a book light. This gives some safety for movement as the source will wrap around nicely. You can add some fill to the opposite side be aware of what your ratio of key to fill is you don't want the fill to kill your key. Or negative fill by setting a flag on the opposite side. You could even place a little lamp in the back ground and play off that and giver her a nice little back light, using a smaller unit that is. Be conscious of your angle of light you don't want to cause a loop lighting effect, where there is just a loop shadow from the nose, this is not pleasing. Have fun with it, there are to many ways to write how to do this. I often like to light the scene and not just the actor keep this in mind and a simple interview can become something amazing. All the best.
-Christopher Arata