On your grandchild's what? Be specific to get specific answers. Anyways that would be:'Mago-san no koto omedetou gozaimasu'.
娘 (musume) is daughter and 孫 (mago) is grandchild, so 孫娘 (magomusume) is granddaughter.
Japanese Eighth Area Army was created in 1942.
Japanese Eighth Area Army ended in 1945.
In Yiddish, grandchild is "enkel" for a granddaughter and "gende" for a grandson.
8 is八 (hachi) in Japanese. To say 'number 8' or 'eighth', you would say八番 (hachiban).
nehead
The word for grandchild in Polish is "wnuk" for a grandson and "wnuczka" for a granddaughter.
New grandchild>>> νέα εγγόνι source: Google Translate
An American born Japanese is called "Nikei America-jin" However, this question could also be referring to generations: Issei = First Generation Japanese, one who has immigrated to another country Nisei = Second Generation Japanese, the child of a Japanese immigrant Sansei= Third Generation Japanese, the grandchild of a Japanese immigrant Yonsei= Fourth Generation Japanese, the great-grandchild of a Japanese immigrant
Mo'opuna wahine
If you mean it to be something like "Number one grandchild" then it is 一番の孫