Yes you can use this lexile level to help show that she is reading above grade level. As the previous poster mentioned this puts her probably at least 2 years above grade level. Keep in mind this is only one way to measure reading level.
What I would talk about is what else but this lexile system you can use to challenge her in reading. Why? IMO this program is good for emerging readers, those who are still learning to read. My experience (and that of my kids elementary school) is it's best for students reading till about 4th grade and at max this lexile level. The problem, is this system sets levels based on complexity of the words & sentences. This works well when a student is still learning to decode. But it doesn't really pay much attention to interest, subject matter and age appropriateness. I found when my son got to this level (in 2nd grade) it started to become harder to find books that he wanted to read & that I thought were of appropriate.
In addition somewhere about the 4th-5th grade, most 'reading' programs move from 'learning to read' to 'reading to learn'. Most of the excellent children literature for 8-12 yrs old are in the 700-1000L. And there is a lot to be gained from reading many of these well crafted books and talking about the themes in the book, the motivations of the characters, and how a well crafted story is written.
My son's 4-6th grade self contained gifted program, encouraged reading of Newbery Medal books for a book "review/analysis" (not a book report) they had to do once a month.
http://www.ala.org/alsc/awardsgrants/bookmedia/newberymedal/newberyhonors/newberymedal
