Social Security and last year's stimulus...?

Ok, one last question about last years stimulus. My parents are both retired and my dad works part time and recieves social security and his pension. My mother is now a homemaker, and just started recieving social security last year but has no job outside the home and no pension. They recieved $600 for the stimulus after filing jointly. Will they recieve the additional $600 that they didn;t get last year this year since she has now earned enough of social security or will the amount they got (umingly for my dad) be it?