Motivator wrote:
I suppose I was analogizing too much from a male perspective, having observed that a speedy, team sport player like a back in football or an outfielder in baseball, is usually able to run 17 or 18 minutes for 5k with training, about 2 or 3 minutes slower than well trained, talented CC runners, which is a huge gap but not nearly as bulging as 19 minutes versus 27+ minutes.
Very few high school football/baseball players could hop into an XC 5k and run 17 or 18 minutes these days. Take an average high school football or baseball team with ~50 kids (football) or ~30 kids (baseball) and toss them in a 5k and you'd have maybe 5 under 20, and most of them will have come from soccer, swimming, or basketball backgrounds.
Maybe it was different in the 1970s, but more likely you're misremembering things. Most high school XC teams--even very good ones--have plenty of guys clustering from 19 - 23 minutes. Great Oak was the best XC school in the country last year and they still had over a dozen guys with end of season PRs in that range.
OP: Your kid is probably bad at XC because short sprinters usually hate XC. A school with a bunch of girls at 19 minutes probably has a solid program, but if your kid's going to practice and run/walking 3 miles easy with her friends three days a week, she's not going to get fast and she's not going to build the aerobic strength needed to complete workouts. The coach isn't going to chase after athletes to make sure they're running; the kids that want to get good at XC will put in the work, the ones that don't care won't.