Got any alternative names for a 'grand-mother'?

As you can see we have been given the gift of a grand child on the way. My step-daughter, who has been with her husband for over 10 years, only got married last year and we are so pleased for them.

HOWEVER I DON'T FANCY BEING CALLED THE TRADITIONAL :Granny, Nanny, Grandma, etc. Does anyone have any unusual alternatives please? I AM GOING TO BE A VERY YOUNG GRANDMOTHER YOU SEE.

Thanks for your help.