Female who weighs 160 and runs 12.4,25, and 56? And TJs 35? How tall are you?
Regardless of height, with times and jumps like that, I wouldn't count on losing too much weiht from running XC. From the numbers you gave us, I'm guessing that most of your weight is tied up in muscle, which means that you probably don't want to lose all that much weight because if most of your weight is tied up in muscle, then if you lose a fair amount of weight (like that 15 lbs you were talking about) you're gonna have to start cutting into that muscle in order to lose weight. I'd expect to lose not more then 10 pounds at the most, unless you've got an odd physique.
At any rate, the numbers you gave us are actually kind of confusing to me, especially with the training the coach is recomending. Do you think you could go into a little bit more detail about your height/physique? It might make some things a little bit clearer. 160 would seem overweight for most females, but your times and jumping don't go along with that. Hence, my confusion, hehe.