When and if she does lift them does she show any signs of discomfort, rearing perhaps? My boy sometimes doesn't let me pick his front legs up as he has a bit of arthritis in his knees and near fore fetlock and he rears up. However, I changed how I was lifting them up - I used to pull at his feather and put my weight into his shoulder but I found that I was just using my weight against his and you can guess who won! I now (correctly!) run my hand down the back his tendon and at the bottom put pressure on with my two fingers, one each side (does that make sense?) and he lifts them up sooo much better. So you need to eliminate if she's trying you out (my boy is a lot better with farrier, knows he can get away with things with me!) and also if she's in any pain. Plus look at the way in which you're trying to lift them up. X

if she is that bad ask your vet to administer seditive id hate to use it but it may work x

Maybe she feels she still can't trust you so she will not let you pick up her feet. So you can try letting her smell your hands then lightly run your hand down each leg and a couple of days try lifting her feet up again and see if she lets you. good luck