Should I contest will?

In the will, my Grandma divided her propery between 3 living children (one has since died)and did not include anything for her 2 predeceased children’s family. In the will, she states that if one of the children predeceases her that their share is to go to their children and wife---and their names are listed out. One of her children did predecease her and the children and living spouse are going to inherit. How is this fair to the other 2 predeceased children’s family who were not listed in the will? If it is believed that the 3 living children
influenced her decision to leave out the other families, is there grounds to contest? A small cash settlement was made to the two children of my Grandmother's deceased children. However, we were not listed to receive any other of the remaining assets. This is a substantial estate.

This is in North Carolina.