It sounds like your mom definitely needs to see an orthopedic surgeon
for evaluation right away, probably followed by a referral to a physical therapist
. You are absolutely correct that it is typically not normal to have that degree of immobility and pain this far out from the original injury
. It will be very important for an orthopedist to be able to evaluate her and make sure that the original injuries have healed properly and that there aren't any sort of new problems developing. For example, it is possible for one of the biceps tendons to rupture, and this can cause swelling in the biceps are and significant pain with moving the arm. It is impossible to say whether this (or something else) has happened to your mom without a thorough physical exam.
Once an orthopedic surgeon has cleared her for physical therapy, then this kind of rehabilitation will be very important in regaining mobility and strength in her arm and that side of the body. Physical therapy is a very important part of recovery for any kind of injury requiring immobilization, and hopefully with an intensive program your mom can recover her strength and begin to feel better.