Re Ontology: I'm probably making a bad explanation even worse, but it's possible to recast the ontology in terms Quine would accept.
Quine rejects any cozying up of the nonexistent with the existent and metaphysics generally. In its place he puts the logical criterion that an entity exists if it can be substituted in a true, well-formed sentence of logic; "To be is to be the value of a variable." However, he does not commit to a specific context for said true, well-formed sentence of logic: mathematics, he notes, is "up to its neck in commitments to an ontology of abstract entities," so there may be an ontology where you do have Pegasus and Daria. They may not be spatio-temporal entites—numbers aren't spatio-temporal entities either—but they exist all the same, and so we don't have to bother with the being of nonbeing.
In "On What Is," Quine distinguishes between meaning and naming, saying that devotees of the notion of "existing in mind" have confused them. A name is shorthand for a (formal) description; meaning is a mental phenomenon that he does not analyze and goes as far as to say is unnecessary for his logical criterion of existence.
So armed, we can say that the name "Daria" with respect to the fandom (our larger context of ontological commitments) unpacks not to one but to many different descriptions. These descriptions can be mutually contradictory, but as these descriptions are not spatio-temporal and all intelligible/significant to the context of ontological commitments—i.e., the fandom—then, by gosh and by golly, they're all Daria because they're all values of some variable. Ditto for all the Janes, Quinns, the Lawndale Highs, etc.
Usually you get only one description of each name per story. But why not several?