Can you describe the one she "runs through?" Does it have a ground line (a pole a few feet from the jump)? You might want to try that. Set the ground line about a foot or two in front of the jump and send her around. Also, who are Lily and Shadow? (I'm sorry, I've been a posting slacker and haven't been on much recently) Which one is the one you're having problems with?
What do you mean by "she's not lifting her feet?" Does she kick the ground poles? I couldn't get Cirrus to stop kicking ground poles, so I got some thick square poles (I used leftovers from my parent's house renovation, but you could just use some 4"x4" poles) and made him keep doing it. The nice thing is that since they're square they don't roll and since they're heavier, they make their point a little stronger (remember to protect your horse's legs with wraps and bell boots, etc. They'll still feel the poles and won't hurt themselves).
Is she doing ground poles OK but knocking over the jumps? If this is the case, you really should get her checked out by a vet to make sure she's not having knee/hock/back problems. Otherwise, you may just need to lower the jumps and practice practice practice. Amir has a great suggestion. Depending on her history, she may not have the required strength yet. It took Cirrus a seemingly long time (although in retrospect, it didn't take that long) to become strong enough and to figure out the whole jumping thing.
Final thought for right now: she may just not be interested in jumping. Some horses like it, others don't. I'm sorry for the super long post. Let me know how it goes!