Your mom has under gone a big trauma and is still coping with the loss. Loss is something that takes time for someone to overcome. For the start, please be patient, positive and calm with her - it will take a lot of patience from you to be able to contain that neutrality. Try and get her to enjoy small pleasures in life (which means you need to spend more time with her) small things everyday. To further help her cope and release the bottled up emotions, kindly contact me for counselling/further guidance. Just meeting someone new can bring in a change.