Since you do not have time to enroll in a new school, why don't you sign her up for private math tutoring once a week? The reading and language arts can be done at home with activity books from Barnes and Noble. You can even order TAG activity books or buy activity books several grades higher. You can purchase Core Knowledge "What Every First Grader (Second Grader, Third Grader, etc.) Should Know" books and accompanying handbooks, for History, Science, Literature, Composers, Fine Artists, etc. These books are easy for kids to read to themselves.
Good Luck!

Also, other excellent excellent schools in BVSD:
Bear Creek Elementary
Southern Hills Middle (win lots of Math awards)
Fairview High (No. 2 in Colorado after P to P)
Horizons Charter
Manhatten Middle