Mom having leg problems, ER stated Edema...has some heel lacerations...?

My mom has had, for a while now swollen lower legs. One was worse than the other. They would continually weep with a somewhat strong odor. She would wrap her leg in paper towels to help it. Being stubborn and not going to the doctor, it got to the point where she couldn't walk due to a sore on her heel on one foot where the skin is very dark. The other day my brother took her to the ER and he said it looks like Dependent Edema. He didn't administer any blood work or urine. They gave her antibiotics and it looks like it's getting better. Swelling has gone down and she's walking better. I'm worried and want her to be able to walk on her own. She has a doc appointment tomorrow so it and she can be fully evaluated. Any idea of what this is? I've done research and found that it can be cause by other issues, but she is in good health (as far as we can see). Diabetes maybe? Hopefully it's not Kidney issues, which I've read as well. Any ideas would be appreciated, hopefully they're positive :)

ALSO, her leg is now blistering, it's covered in dry skin. Almost seems like her leg underneat his shrinking and all the dead skin is hardening and coming off. Sorry to be graphic, but I'm sure it will help out. She's also walking a bit better and her feet are hurting less. Dunno if this is just some sort of infection. My concern is that it has gone to her bone, which I hope doesn't keep her from walking without assistance.

Make sure she keeps the doctors appointment. She needs a full work up. It could be her kidneys, heart, Diabetes, liver. Once the doctor finds out what is causing the swelling he might put her on a diuretic to get rid of the fluid which will help those wounds heal. All that water is trying to get out of her body, so if the kidneys don't push that fluid out, it just seeps through the tissues. If the wounds don't heal take her to a wound care specialist after the primary issue is under control.

if your doctor can not help she must go to an other it maybe lympodema. i have it. miss diagnosed for ten years.