I do not think that someone named
Elina would inevitably be called
Ellie. Not all Elizabeths and Elinors are called
Ellie. My brother is
Nathaniel, but he has always been called
Nathaniel, never
Nat,
Nate, or
Nathan.
Here are some combos
Elina KatherineElina ClaireElina FrancescaElina Theodora Elina Jane
Hope these are not too far off.