What assurance does Grandmother offer to Mother and Tushi after she realizes they have been crying over her approaching death?

When Grandmother sees that Mother and Tushi are crying, she tells them that they should not cry for her or for Grandfather. She explains that they, the young ones, do not need her now, but Grandfather does. She says that she simply wants to follow Grandfather down the Trail to the Land of the Dead. They have spent so much of their lives together that she says she does not know how to live without him. In essence, they should be happy that Grandmother would be reunited with Grandfather.