New runners with negligible talent suddenly runners a big PR, what causes it?

Coacher wrote:

A freshmen girl joined our XC team this year. I can say she has negligible talent; slowest girl on the team. She required too much attention but overtime she was left alone and I focused more on my faster girls.I coach the schools girls team. This freshmen had no friends, was constantly injured, was lazy, had no pain tolerance. I gave up. She was a back of the pack girl. She suddenly got her 5k down from 29 minutes to 26 mintue in a course of less than a month. On the same course, almost catches up to 1 girl who usually passed her and passed 2 girls who usually passed her. Should I invest more in her or is this just a fluctuation. She also wants to quit XC. I told her if she wants to she can. Should I persuade her to continue just in case she has potential ?

Coacher wrote:

A freshmen girl joined our XC team this year. I can say she has negligible talent; slowest girl on the team. She required too much attention but overtime she was left alone and I focused more on my faster girls.I coach the schools girls team. This freshmen had no friends, was constantly injured, was lazy, had no pain tolerance. I gave up. She was a back of the pack girl. She suddenly got her 5k down from 29 minutes to 26 mintue in a course of less than a month. On the same course, almost catches up to 1 girl who usually passed her and passed 2 girls who usually passed her. Should I invest more in her or is this just a fluctuation. She also wants to quit XC. I told her if she wants to she can. Should I persuade her to continue just in case she has potential ?

Coacher wrote:

A freshmen girl joined our XC team this year. I can say she has negligible talent; slowest girl on the team. She required too much attention but overtime she was left alone and I focused more on my faster girls.I coach the schools girls team. This freshmen had no friends, was constantly injured, was lazy, had no pain tolerance. I gave up. She was a back of the pack girl. She suddenly got her 5k down from 29 minutes to 26 mintue in a course of less than a month. On the same course, almost catches up to 1 girl who usually passed her and passed 2 girls who usually passed her. Should I invest more in her or is this just a fluctuation. She also wants to quit XC. I told her if she wants to she can. Should I persuade her to continue just in case she has potential ?

Coacher wrote:

A freshmen girl joined our XC team this year. I can say she has negligible talent; slowest girl on the team. She required too much attention but overtime she was left alone and I focused more on my faster girls.I coach the schools girls team. This freshmen had no friends, was constantly injured, was lazy, had no pain tolerance. I gave up. She was a back of the pack girl. She suddenly got her 5k down from 29 minutes to 26 mintue in a course of less than a month. On the same course, almost catches up to 1 girl who usually passed her and passed 2 girls who usually passed her. Should I invest more in her or is this just a fluctuation. She also wants to quit XC. I told her if she wants to she can. Should I persuade her to continue just in case she has potential ?