How many miles should a 14 year old girl, [88-90 lbs] be running a day to stay in shape?

There is no way to get toned fast, period, end of story, its just not possible. If your talking about you want some abs and some definition in your arms and legs that would take six months MINIMUM, if you use weights and do sit ups for your abs. The one mile thing should gradualy be moved up to two, but dont over do it