Nomoremagnolia - Have a lovely holiday!!
Woodmouse - So long as you are just getting prepared, then that is ok Just don't be tempted into testing early
Bellabear - Great question!! And one that DH and I have discussed at length.
Gilly - We don't have the normal family stereotype either, so it's not as straight forward as for some.
I personally think it should be up to our parents to decide what they would like to be called.
My maternal grandmother was "Nan". My paternal grandparents were "Granny" & "Grandad" - my Grandmother despised the term "Nanny" - she used to say "I'm not a Goat!"
DH's paternal grandmother is "Nan" - His maternal grandparents were "grandma" and "grandpa".
I know my Mum will want to be called "Nan" and MIL will definitely want to be called "Grandma". Both our Mum's are with new partners (my mum divorced, MIL widowed) but they are relatively recent additions (!) so they are not really considered step-parents as we'd already grown up and left home before they were on the scene. So we thought they would just be called by their names. Eg. Nan & x and Grandma & x. And we will explain about their real grandfathers.
Friends of ours whose parents all wanted to be known as "Grandma" and "Grandpa" all just had their names added by the children "Grandma x" and "Grandma y" Thankfully we won't have that issue.