Dative or instrumental case hegemony?

Question

I am not sure how to interpret the pronoun in this one:

Ей вы́слали приглаше́ние, но она́ не пришла́.

Obviously the second "she" is in nominative, but what about the first one?

Looking at the declension alone it could be either dative or instrumental.

I can see arguments for both: dative because 'she' could answer the 'to whom/what' of the verb 'sent'. Instrumental because 'she' could be the 2nd direct object alongside the invitation. I also considered instrumental via the logical subject route but since the phrase does not mention one who could function as the sender, I doubt she becomes the logical subject by default.

Is there some other rule that I do not know about? Perhaps it has to do with the 2nd 'she'?

Answer 1

As observed by Quassnoi, the Instrumental would not make much sense in your example.

However, there are many other phrases that could be analyzed either way, for instance

Ей было сделано предложение,
- most probably means "there was an offer/engagement made to her" (Dat.), but technically can be read as "An offer was made by her" (Instr.)

Note however, that feminine nouns and pronouns have two forms of Instrumental, «ей» and «ею», and only the former one can be confused with our cases. Every time when a speaker feels that there can be an ambiguity, one would simply chose the unreduced form.

Ею было сделано предложение, "an offer was made by her", certainly Instr.

So you if you need a rule of thumb, you can always try to interpret «ей» as Dative first, and then as Instrumental if the Dative does not make sense in the context.

Answer 2

Grammatically, this could have been the instrumental indeed, however, semantics of the sentence rule this possibility out.

Parsing this sentence with ей in instrumental would yield something like "the invitation was sent with her (using her as a tool)" which makes little sense.