The word for calling her is "oma".
* If your husband's children have accepted you as a step-mother and you get along then you would not technically be their true grandmother; but, if his children want you to be part of their children's lives then yes, you could be a grandmother. The children may with to call his former wife 'grandmother; granny, grandma' but they could call you 'nanna; nanna Mary (by your Christian name) or may have a nickname for you.
The grandmother in Spanish is "la abuela"
Your grandmother's grandmother is your great-great-grandmother.
Grohs-mammi (That is the Ohio Pennsylvania Dutch dialect)
Grootmoeder But that's a pretty 'stiff' term, 'oma' is used most of the time.
Yes, "oma" means grandmother in German and Dutch.
'grootmoeder' but that's an old word so everyone says 'oma' now and that means something like 'granny.
Great Grandmother
Your grandmother's mother would be your great-grandmother.
Your grandmother's mother would be your great-grandmother.
what do the dutch call sumatra
She is your paternal grandmother.