Re: how to acknowledge grand parents in a wedding invitiation
or you could write Mr. and Mrs. (Dada's Name) cordially invite you to the marriage of their beloved granddaughter,
(Your Name here),
Daughter of Mr. and Mrs. (Your Father's Name Here)
with
(Fiance's name here)
Son of Mr. and Mrs. (Your sasur's name here)
etc etc
I've seen a lot of invites done this way