Sometimes the hand is left in a fist. Not only do u have to start all over again, but u have to start with an adult body. Both my hands have been fisted. I type this with 1 finger on the hand that was lesser. I knew if I could get 1, I'd get the other. It's coming along, but it doesn't type. Although they both open n close n there is finger individuation, there is more to do. It's already been many yrs. What I describe here can span a few months or a few yrs, it depends on the condition n how fast your body wants to work. I wish mine was over night, but rly it's yrs.
"Digits should move together. Don't worry about finger individuation yet. First get movement established" http://thoughtfulveg.blogspot.com/2014/11/neurons-that-fire-together-wire-together.html
If your hand is fisted, hold a rolled wash cloth. This will give your hand some separating space. The fingers won't be against the palm of the hand. It reduces and may even stop sweating of the hand. It gets the hand used to being open a bit.
A regular to thin wash cloth should do well for holding. The thicker luxury ones may roll too wide to hold.
Throughout the day, squeeze the cloth. You will make your fist tight. It will be in tightening your hand that you make it looser. Squeezing tighter will be isometric exercise.
Eventually you graduate and move up to stress balls, the kind you squeeze in your hand. I used a cheap foam one. Some companies will put their logo on them and give them away. You can find plain ones at stores. These are the cheap foam ones. They do go up in price as you find the gel ones used in hand therapy.
I actually found a picture of the one tied to my wheelchair. A nurse bought this with her other shopping at Wal-Mart. She thought of my fisted hand. She put a hole in it, and threaded gift-wrapping ribbon through it. She used the ribbon to tie it to my wheel chair.
When you squeeze your stress ball, your fingers stay together. You are not individuating them, yet. Finger individuation doesn't come right now. It is the next step.
From the squeeze ball, and even before you are done with it, you can start doing hand therapy exercises. Don't worry if you can't hold your hand wide open. That is what you are striving for. Just do as much as you can right now.
*I use the videos for their information, not their company.