G.B.
Start keeping her up later and later and later until her clock changes. Biorhythms can be changed. Otherwise no one in the world could ever work the night shift.
Once she is sleeping later you start putting her to bed around 9pm or so and she should adjust.
The earlier she goes to bed the earlier she will get up. It might take 6 months of her staying up to 10 or 11 but her biorhythms will eventually change.