I think some other posters have it correct that the other girl is the one who is much slower in CC.
But still, you sound like a strength runner - so you are stronger in CC than in track. What does this mean? and how do you overcome this?
It means the longer and the tougher the race the better you will do. I am the opposite in that I always had a great kick - so for me the goal in racing was to just try to stay close. If I could, I would normally beat those I am chasing. but if i get broken (gapped by too much) I would tend to give up - and not finish strong. After losing a few times to strength runners in road races (as short as 2 miles) I realized something strength runners do. The surge and gap me. I was broken by this guy around the mile and gapped big time...but still put on a kick even though I knew I couldn't catch him - guess what? I didn't catch him, but I made up so much ground, I realized he has no kick...the next time we raced I just let him go but tried to stay within range - and beat him easily.
Am I right in assuming that you have no kick - like these other strength runners?
If so, you must learn to be competitive on the track you have to gap people by making surges and such in a race. You will be strongest compared to other runners in the middle of races - so that is when you need to make your moves. So in a 3000 on the track - the moves start for you on lap 4,5,6. The mile will be tough for you, but hammer the 3rd lap.
How should you train? One big problem coaches have when it comes to strength runners is they have you do too much (or even any speed). Speed workouts don't really help you much because they just wear you out - make it harder for you to recover for the next workout. You need to train to your strength by doing tempos and steady state runs:
like 4 miles at a good effort (not a race effort, and maybe starting out moderate and getting faster or practicing surging in the middle)....or longer runs of 6-8 when you just try to hold a solid pace = called steady state. If you cut out speed workout and do these instead and find that it works - then you know that you are a strength runners and that you almost need to avoid speed workouts (you can do some speed, just not making the whole workout speed based).
example of how to incorporate speed for a strength runner: do strides of 50-100 meters after your tempo or steady state. Gradually add a few (2-3) 400s as you get closer to racing season, but never just go from doing no speed to say 8x400 = those kind of workout might sap you. Biggest mistake you could make would be to do what others do by sharping before big meets with speed only based workouts. you don't need these kinds of workouts. Build/Train/Race to your strength.
You may never develop much of a kick - and that is okay, as long as you learn how to win by gapping others before it comes down to the kick. In CC the course is what is helping you gap other runners because they lack the strength to keep pushing after hills, etc. That is where you beat them.