Muscle soreness

Half marathon training
J reports some impressive progress in running, but also a little soreness after workouts. She's also kicking her ankles from time to time and wonders how to stop doing that.
Great questions.
Assuming she's not sneaking in an extra running workout here and there, J's soreness might mean she's pushing it a bit. Her current net pace is 10 min. per mile, which is fantastic at this point. However, she doesn't have a big running base yet (a lot of miles under her belt), so her muscles and knees are still adjusting to the workload.
I'm not too worried about the muscle soreness, particularly if it goes away before the next run.
I would pay attention to the knee soreness. It sounds a little like what they call runner's knee. It's not serious, but it's pain you don't want.
Do this exercise: Stand in front of a chair, put both arms straight out in front of you and slowly lower your butt to the chair. Keep your back straight. Don't actually sit, and don't let your upper legs go past a right angle from your lower leg, or past parallel to the floor. Put a pillow on the chair so you don't go past parallel. Hold at the lowest point for a 3-5 count, then slowly rise. Do three sets of 12 every day. When these get really easy, hold longer at the lowest point. This will strengthen the muscles and tendons that support the knee and help to eliminate your knee pain. I've done it myself and it works.
Until J actually does a 5k race, she should consider slowing the pace a little. Perhaps start at 10:30 and speed up to 10. The time to push it is during a real race or time trial. If all the pain and soreness goes away before she races she could start running faster sooner.
Ice is surprisingly effective for sore muscles and knees. Use an ice pack or even a bag of frozen peas and apply immediately after a run. Keep the ice on for 15 min. per site. Ibuprofen works well, too, but ice is better, since it's natural.
We've all been through the kicking thing. It's not clumsiness, but it could be running style. Proper form is important to efficient running and in theory would reduce the ankle kicking. Remain erect while running (not at attention, but erect). Imagine that you are running on a stripe, and try to land right on that stripe with both feet. Don't raise your feet any higher than is necessary to take a stride. The higher you lift your foot the more energy you expend, so keep them low. A high stride might be the main reason for the kicking. If all else fails, mention this the next time you buy shoes. There might be a style they can put you in with smaller heels.
Good luck, and good job!