Your wife and child may have been granted visa if the hospital sent the letter of support. But does it have to be all of you?
My wife and 2 years child applied for travel visa for treatment my son, he has got bone disease, and we got free treatment from Canadian hospital, so we applied for the visa, our canadian friends also sending supportive documents, but before reaching the visa supportive documents to High Commission, New Delhi, we got message "Your processed visa application ref no. ........... has been released by the Canadian High Commission/Consulate to Delhi/Chandigarh Centre" and we check visa tracker that we got message "Passport dispatched by OC Delhi OC on 13/12/2011 and is in Transit."
we can't understand, our sponsor documents has not been reached to the Embassy but they already decide. Is the visa rejected or not? please suggest me, why this happen?