Is your oc version of Rick Sanchez has their own Diane?
Yes, most of them do, actually, though since I am assuming it's R0 we're talking- yes, he does, though it's rather complicated with her.
She's alive and well, though she doesn't know what became of her husband and hates the guts of the Rick that replaced him in their dimension after R0 disappeared. He was taken in by the federation around the age of 30 and got his memories erased, he's pretty much unaware he even has a family.
Later on in his story though, they do reunite. Not sure if I posted it here, but here they are:
They are from a dimension where people have summonable wings based on their personality (idea belongs to a friend of mine, will pop in their tag right away)
She eventually dies as well, though, and R0 goes back to being a mercenary, though then he's just working for himself and calls himself Ace instead.
Anyhow, that's that for my oversharing!