I'm sorry that you're having trouble with your hen. How old is she? The molting itself is probably normal if she's over a year of age. Her odd walking may be normal, too--I've noticed that when my chickens molt, one hen in particular starts walking strangely (backwards, low to the ground) at times. I think its because the new feathers growing in feel odd, and she's trying to escape them.
Does she still appear to be eating enough? Molting places strain on bird bodies as their energy is focused on making feathers, so I'm not surprised if they get a bit thin during the process. However, there could be an underlying problem. Has she ever been wormed? If not, then I would worm her with a broad spectrum wormer like Valbazen, SafeGuard, Worminator(contains Flubendazole and can be purchased online from here:
http://www.twincitypoultrysupplies.com/store/index.php?main_page=product_info&products_id=584). Don't use Wazine or Ivermectin, as they only work on a couple types of worms, and I've heard that Wazine (I believe--someone please correct me if I'm wrong) can cause feather deformities if used during molting.
The tipping over, IMO, is probably happening because she is weak from not eating/worms.
Other than that, it seems like you're doing everything you can. Keep trying to get her to eat as much nutritious, fatty food as possible, and watch for any other symptoms.
