what is a likely/possible progression for this girl in her freshman year of high school?

Too many obscure race distances. Is this Oregon or something?

Indoor track, particularly for high schoolers, always seems to have obscure race distances.

This girl could be very good. A distance runner with a low 60 quarter as a FR could be lethal if she developed aerobically.

Does she consider herself more of a 400/800, 800/1600, or 1600/3200 runner?

she ran around a 66 400m last year earlier on in the outdoor season

i think she considers herself a 800/1600 runner but when she was younger she went to nationals in the 3000m

Freshman mileage for xc - 35

Sophomore - 50

Junior - 50-55

Senior - 55-60

Girls don't always have the same linear progression that boys do, especially in high school.

I always go back to this one story when this topic comes up. I was back home watching the state xc championships a few years back, and this freshman girl absolutely obliterated the field. Won by 20+ seconds and looked easy doing. After the race I turned to my friend and said "she'll never win another state title". The next year she finished around 12th, year after that she got 18th, and her senior year she was 25th.

The moral of the story is, girls are all over the map in terms of their natural progression in high school. Some of them hit puberty and get better, others get worse.

So to address the OP's question, it's possible that she'll break 18 by her senior year. It's also possible that she'll never pr in the 5k again.

Bonkers - Agreed.

What I've noticed is that sometimes it is less about the actual physical maturation and more with the fact that they usually have a season where they will have to do more or work harder to achieve the same previous results and that doesn't sit well with most girls. Instead of putting forth more effort for the same result, they'll reduce effort or maybe keep it the same and spend more time on other pursuits (the boyfriend, school, etc.)

This doesn't happen with guys as much. They usually get a performance boost their sophomore or junior year on the same mileage. The increased strength and lung capacity helps them whereas girls tend to add non-locomotory weight.

So in a way a lot of it is about psychological momentum. The girls who get over the whole "doing more for same results" conundrum can eventually move past it.

That being said, there are some situations where the girl matures and it takes them to a point where reasonable training won't overcome the maturation.

The above two posts are dead on.

Girls that get through generally come out better. But they have to overcome those changes stated above.

Competitive from age 9 and a 21 min 5k doesn't really correlate to the goals stated. But if she's more of a track runner than those might be reachable.

puberty.

She will soon either get a lot better, or lose interest.