I think everyone needs different amounts of sleep, no one person is the same. In my household, 9 or 10pm bedtime is extremely late, but that's my household only. I certainly don't think there's anything wrong with that doing. My DD1 is in bed by 8pm and sleeps till 8-9am.
You say you think she may need more sleep. Is she looking more tired during the day or at night? If she is, then you could try bringing her bedtime early by say 30 minutes to begin with. But if she likes to see Daddy before going to bed, than that might be tricky.