Firstly, if your horse is lame & currently suffering a laminitic 'attack', get her onto soft footing & off the grass &/or rich/starchy feed she's on, ASAP & call a good equine vet immediately.
If not the above, what's going on? Has the horse already got mechanical changes from chronic laminitis? Is it just 'low grade'? More info & pics if you want any specific advice.
I was wondering what methods you have used or methods you have seen used before that work for a horse with laminitis?
Check out hoofrehab.com & barehoofcare.com for starters, to understand more about what may be needed, and safergrass.org also has some good diet/metabolic related info.
Very basically, there are a few things that are necessary; addressing the cause, which is commonly diet related; good frequent trimming which will get/keep the feet well balanced and take the pressure off compromised walls/laminae; hoof support/protection, wherever necessary(bad cases may need full time support even in the paddock), that supports the *entire* base of the foot and doesn't peripherally load the walls.
The farrier has told me to just exercise her up and down hills because it will help the hoof to grow the right way.( I thought you weren't supposed to exercise them at all while they heal??) he also said to feed her copper sulphate to help repair it.
If the horse has been well trimmed so as to alleviate/avoid further damage and if she can exercise comfortably - be that bare or with boots or such - exercise is generally a good thing. It's best not to coop them up, but if she's sore, not trimmed right, etc, don't force her either.
I would NOT feed CS except on advice of a nutritionist personally. If you do, feed it with dolomite(calcium & magnesium) and literally a pinch every few days is likely enough. It's a heavy metal & toxic in excess. So saying, copper is indeed one of the trace minerals necessary for good hoof growth that is commonly deficient in the diet. Others include zinc, magnesium, iodine and amino acids/essential fatties. I'd consult a nutritionist (independent of feed co's) or use a program such as feedxl.com to work out what your horse needs.