Cyclone,
It is too bad that she did not work on finger range of motion (ROM) (if the fingers were free to be moved, that is) while in the cast. Finger stiffness is so much easier to prevent than to treat. But, that is neither here not there now.
It is usually best to warm the hand up first, to make the soft tissues more pliable. The best way is with a paraffin wax bath, but if that is not available, moist hot packs or soaking in hot water will do.
Active ROM is best, which is where the patient uses his/her own muscles to move the joints. But, if this is not getting the results, then passive ROM will also have to be employed.
In active ROM, to get motion at each of the individual joints, a technique of blocking is used. Which is basically using the other hand to hold the joints NOT being worked on, stable in full extension. Then concentrate on moving just the joint being emphasized. If you have questions about exactly how to do this, have her ask the therapist the correct technique.
With passive motion, that is using the other hand to help bend the joints. Or having an assistant do it. However, if the fractures are not completely healed, the assistant has to be careful to not put too much pressure on the joints. Stiff joints can transfer the stress to the fracture site. So, if pressure on the joints cases sharp pain in the fracture site, the force needs to be decreased.
A great tool for finger motion is TheraPutty. You can get it from the occupational therapist. It comes in different colors, depending upon the force needed to squeeze it. The putty allows for a full ROM of the fingers, all the way into the palm, while strengthening the muscles in the forearm. The putty can be used while watching TV, reading a book, etc. Just don't get it in the carpet (it's not like PlayDough).
Getting wrist ROM is the same. It is just a matter of moving it in all planes: flexion, extension, side to side (radial and ulnar), and circumduction (around in circles). Passive ROM can be done by placing the palms together in a "prayer" position, then moving the elbows apart, causing the wrists to extend. The same can be done by placing the backs of the hands together, to get the wrists into flexion.
There are some devices that the therapists use, which are basically a handle with several wire loops on it. Each of the loops has wooden beads on it. The idea is to move the wrist to get all of the beads from one side to the other. It is just a devise so the therapy doesn't become boring. There are several of these types of things out there.
Once gross motions of the fingers and wrist are obtained, then the therapists usually start on occupational or recreational specific motions. The motions that the patient may need specifically for his/her job, activities of daily living, or for hobbies. These can be such things as using tools, typing, mouse use, buttoning shirts, using zippers, preparing food, hygiene, cleaning house, sewing, knitting, etc.
It is going to take a lot of effort, motivation, and time to get the stiffness out. When joints are not moved, they become very fibrotic and it is difficult to get the motion back. However, people come out of casts everyday, so this is a common problem to be worked out.
With repeated sessions, usually patients can get all, or the majority of, their motion back, to at least a functional range. Again, if you heat up the tissues, it is easier to get the tissues stretched and the joints moving.
Hope your mother does well with her rehab. Good luck.
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