Brown cow really looks like she has an infection in that leg. If you look close at her picture it looks like she has a split in her outer claw which probably where it started. Antibiotics and soak the foot in Epsom salt water if you can.
Can you get loose salt /mineral? We usually use Purina Wind and Rain. The cows are able to consume the required amount of minerals much easier in a loose form than a block.
Look at the tags of the milk replacer. Get one that is all milk no soy. Feed what's recommended on the directions for now. I usually end up increasing it to more than it says but not until the calf is older. It is expensive bottle feeding a calf. Like the others said I would keep trying with mom...
We had one that lost one rear hoof last year due to frostbite. We kept him and his mom locked in a corral until weaning and then fed out the steer to butcher at 9 months. His foot was just kept clean and dry.