I am suprised she didn't have you do hydrotherepy, that has been the most effective treatment for my asthmatic lo's deep wet coughs he gets with colds. Give her a warm bath and raise her body temperature. Wet a recieving blanket or small towel in very cold water and wrap that around her trunk, mostly chest area, and then wrap a towel around her and the cold wrapped towel. Sit with her for about 20 minutes until the cold towel is warm again, this means the therepy is completed. My ds doesn't seem to mind the cold towel if I wrap the big towel around him quickly afterwards and hug him. We just read books for a bit after the bath. Do this every day for 3-5 days and it is an incredible healing tool. It makes blood rush to the cold area and promotes healing. We have had absolutly incredible results with it.
Anti biotics sometimes are the only thing that can heal a chest infection or like we found out when our son got pnemonia...no choice really. It does sound like there are a few other things you can try before resorting to anitbiotics. Remember although they shouldn't be the first line of defense they aren't evil and can fix her up if an infection she is struggling with is really the problem.
Good luck, it is awful when a lo is sick!