Kim,  

There was a show done on NPR by Tom Ashbrook on grieving back in January.  He sadly has recently lost his wife but the show was not just about spousal grieving.  I found it quite interesting and the comments were also helpful.  It might give you some insight. I had responded in the comments to a woman who was asking what she could do to ease the pain of her loved ones since she herself was terminal with an aggressive form of cancer.  You might see my post.  Otherwise it might give you some feeling of what to expect and how you might handle it.

I think it speaks volumes of your love for your mom and your own personality how you are reaching out knowing what the future holds.  I will include the link to the podcast.  Hope it helps.

http://onpoint.wbur.org/2015/01/02/grief-mourning-tom-ashbrook-family#comments