It is long past being patient. You are not being given the correct information. First of all, never accept information from the VA unless it is in writing. You will never get the same person when you call back. It is the luck of the draw when you reach someone at the 1-800 number. There are a few good individuals working the phone-lines but most do not want to work in that section and they are only interested in getting you off the phone and take the next call.
VeteranAid.org has an article posted with detailed information regarding the lack of proper training for the VA employees and another article regarding the very high percentage of wrong information being put out from the 1-800 number.
I recommend you complete the attached VA Form 21-22a that will give you the authority to act on your Mom's behalf and then take charge. If you are not satisified with the response that you are receiving from the VA vet rep, then ask to talk to a supervisor. Don't let them tell you that you cannot not speak to a supervisor, it is your right.
If the VA never made a determination on the original claim then it is still open and your Mom is entitled to the earlier effective date. Once you submit the attached form you can request copies of any correspondence that they claimed was sent out on your Mom's claim. Call the bluff.
Under their 'duty to assist' obligation, they must let your Mom know what is needed to complete her claim. Needless to say, your Mom has a lot at stake here and you must take some quick and aggressive action.
Please keep us informed of the outcome. We have seen some claims get approved within 6 weeks. Taking a year to process is unacceptable.