1) Can't go full detail, but not that high. Low-moderate mileage, often 45 min easy runs at 8 min pace with lots of strides. Sundays off cos of religion unless there is NXN or something. Focus was on aerobic development with key workouts.
2) CV is 30-35 min race pace, standard workout is something like 6x1k@CV (200m rest), 8x15s hill sprints, 8x100m strides, all in one session. These sessions gave her the outstanding stamina she has now.
3) Tinman explained it in a coaching video. She and her Stillwater friends/parents hired Tinman to coach them after Project Gold Camp last summer. He communicated with their coach and prescribed them workouts. Improvements in that magnitude (and essentially the whole team improved) are just not possible without a major change in coaching philosophy. Many HS coaches are good guys, carefully manage the team, make sure they feel well and support them/motivate them to train, but when it comes down to the training plans and philosophy, elite coaches like Tinman/Canova/Bideau/Lydiard/Schumacher etc. are on a whole different level.
Tinman said, like the other poster previously pointed out, that her coach previously used a lot of hard speed intervals, anaerobic capacity sessions and speed endurance in her training (short recoveries) but completely neglected short sprints with long recoveries (neuromuscular sessions). As a result, at one point her range was 2:23-5:04-10:40, simply because the training didn't develop her 800/1600 ability. She also noticed that under her old coach she always lost endurance after XC or at the end due to the extreme focus on speed with short recoveries.
She is a great runner, very motivated and always wants to do her best, so choosing Tinman after the camp last year was a no-brainer and really allowed her to reach the next level. More HS kids could be good like that if they would also get a real coach to prescribe them workouts.