I'm not sure what the fastest 3.5 mile run ever is, but i do know the fastest 5k ever is a 12.37.35 by Kenenisa Bekele (Ethiopia) on May 31, 2004. www.chacha.com/question/what-is-the-world's-fastest-5k-running -time
The fastest mile ever run is 3:43.13 by Hicham El Guerrouj of Morocco in 1999. The fastest women's mile is 4:12:86 run by Svetlana Masterkova of Russia on August 14, 1996. New record! men: 2:02:01 (just kidding)
The time in which an individual can run a mile is determined by their personal physical fitness. The fastest a 13 year old boy has ever run a mile is 3:55, by Jim Ryun. It is advised that one speak to their health professional before beginning an exercise program.
maybe around 3 mins, but it depends on her speed and how fast she can run!! Fastest mile ever run is, I believe 4 minutes. So, a good mile and a half would be about 9-11 minutes, at a good pace, but like the previos poster said, it all depends on their speed.