So which Melinda was she

we never really find out and i don't think we are supposed to know.

at the beginning, the guy at the table says "I have a story and you tell me if it's comedy or tragedy" and I am guessing he says "So a complicated and troubled woman crashes a dinner party, all the friends are trying to set her up, something bad happened with her marriage" and thats about it. Maybe he gave more details but we don't know what details--- so we dont know if she actually killed her ex husband and lost her kids---or if she never had kids and never killed anyone--but the central idea is the same just without those details. i dont think it is supposed to matter who the real one is or what really happened because its all just a re-told story at a dinner table

but as always it can be up to the audience's interpretation and for me-- i always felt since they actually show more of the tragedy portion of the story and it has way more details, that one felt like the real one to me. but it's never said or even hinted at.