It is generally recommended to start with a Levemir dose that is 30% less than your current Lantus dose when making the switch. Amethyst is currently on 8U of Lantus, so that means the suggested starting Levemir dose for her would be 5.5U (technically, it's 5.6U, so I rounded to the nearest dose that's actually measurable on a syringe with half-unit markings).