OK, you have 13 weeks and need to average 1.5lbs weight loss per week to meet your goal. For a female that's pretty much pushing the upper limit as far as what you can lose. You should expect to lose some lean mass along the way as well, remember even water counts towards your LBM. This equates to a 750 calorie a day deficit. I dont know what your weight of lean body mass is but it's safe to assume you are going to be fairly low calorie and fairly high cardio to make this happen. What do you have layed out so far?