Fatigue secondary to medications can be a very difficult symptom to deal with. For most medications that cause fatigue, it just takes time for the body to get used to them. This may be the first piece of advice your child's doctor
may give to her.
The first step towards helping your daughter's fatigue problem is to make sure that there is no other contributing factor. She needs to be getting 7-8 hours of uninterrupted sleep. She should avoid drinking caffeine after noon and avoid drinking more than one alcoholic beverage per day. She needs to develop a routine of eating a healthy set of meals and exercising every day. If she absolutely cannot go through a day without laying down, she should have a planned nap of no more than 45 minutes. Finally, if her fatigue is completely interfering with her day despite these things, she should try switching her medication regimen.
I suggest that you schedule an appointment with your child's psychiatrist
(or whoever is treating her bipolar disorder
) for a follow up appointment. If the fatigue continues, and does not get better with time and a few interventions, then changing her medication should be considered. There is more than one medication that works for bipolar disorder. Good luck.