Well, in order for us to know, we first must have to understand how many miles it takes to get one lap around the school track.
One mile, as there is no more information pertaining to how many miles it takes to get around the school, would most likely equal to one lap, therefore she ran 35 miles.
If this is incorrect, provide me with more information on the question in the comments, and I will try to help as best as I can :)