Hi Jackie, first off, as a parent and grand parent I am soooo sorry your family is going through this.
I also want you to make sure that before you mention being a donor or start testing that you apply for life insurance. It can be difficult to obtain after donation, the rates can become a lot higher. Sorry, that is just the truth. Hope you also have some disablility insurance or at least family leave time. I have disability insurance that I have used several times in my life, it has been well worth the cost.