Normally there is a time limit of one month for making an appeal. This will run from the date of the decision letter informing your wife that she had been placed in the WRAG.
There is scope to have the appeal period extended for up to thirteen months but in order to request a late appeal, your wife would need to demonstrate good cause, and that there were exceptional and/or mitigating circumstances why the appeal was not within the prescribed time limits.
If good cause cannot be shown, your wife (unfortunately) will have to undergo the WCA process again under the revised legislation, using the new ESA50.
Nothing on this board constitutes legal advice - always consult a professional about specific problems