hey heather
the use of crutches has undoubtedly caused problems in your daughters shoulder. i dont know whether it is rsd/crps spread or if it is just muscle/cratalidge/nerve strain because all of her weight is being transfered through her upper body to relieve the strain walking caused on her lower body. i damaged my shoulders because i was on crutches because of knee injuries so often.if she is on crutches that go under her armpits you may want to ask her doc/pt for canadian (or wrist crutches) they will change the area that pressure is being applied in her arms and alter the range of motion which might help. if she is already on the canadian crutches she may need to try a walker for a little while. i know the idea of a walker for a kid is depressing (crutches are lame but doable...a walker is so far beyond lame it is down right embarassing)...she may be able to use crutches on a limited basis at school and then switch to get around elsewhere.
the shoulder problem may be a sign of disease movement but it may also be the result of repetitve movement, talk to her doctor.
if the doctor believes the rsd/crps has migrated you may want to discuss a stellate ganglion block in an effort to stop it in its tracks before the nerves are permanatly impacted...but i wouldnt take that leap without a serious discussion first.
it may be a simple fix (or as simple as a fix can be when you are dealing with this disease)...our bodies were designed to function as bipods...walking with the use of our arms was never part of the equation. check her crutches if her complaints are based on shoulder range of motion pt can probably help her.
good luck and i hope you have a wonderful holiday