Your grandmothers family is a very interesting family.
The original name is IALLINOS (in Cretan dialect GIALLINOS) and is going back over 700 years. Some males are known with the title "ARCHON" which is the equivalent of "Nobile" (Noble). Some did have the title "Domine". After 1669, many migrate to Zante, Corfu and Lefkas.
The invitation simply says: Mr & Mrs George Panagiotopoulos invite you in the wedding of their son Nikolaos with Chrysanthe Giallitakis. On the other site, Mr & Mrs Peter Moschovitis invite (their friends) in the wedding of their NIECE Chrysanthe with Peter Georgiou Panagiotopoulos.
Taking into account that Mr Peter Moschovitis was Chrysanthes Uncle, that means either her mother's name was Moschvitis or Peter Moschovitis's wife was her mothers sister.
Another good family is:
Moscovitis is also a Cretan family of Venetian descent, Original name was Mosco (and any name starting with Mosco is related like Moschonas, Moschopoulos, etc). Moschopoulos was Metropolite of Crete 800 years ago.
Another name that may hide a surprise is Mavromichalakis it could be a Cretan nickname but also it could be variation of the name "Mavromichalis" which is a significant name in Modern Greek History.