My daughter is 8 and wakes up every night crying when i ask what is wrong she doesn't know. am concerned it's over a week now?

How so: If a kid wakes up in the first hrs of sleep it can be a night terror.This is related to sleep walking & talking. They often cry/fight but if left alone will re-sleep in 5 min & never remember in the AM.They are hard to wake if you try. If they wake later in the night it is often a nightmare & they wake immediately & recall the scary events. Many are due to poor sleep habits.