I might’ve found Krazy 8’s sister in the Breaking Bad universe.
Remember the principal at the school Walt used to teach at? Her name is Carmen Molina. Now, according to ancestry.com (yes I went to ancestry for this), Molina is not a very common surname, and there are only 514.000 birth records of it ever made. On forebears.io, it’s stated that there are only 85.000 Americans with the surname Molina. Meaning only 0.03 percent of Americans have this surname, ABQ’s population is around 560.000, so there would be approximately (very roughly approximately) 168 Molinas in ABQ.
Now, does this mean it’s absolutely impossible for two unrelated Molinas to live in ABQ? Nope. But does it mean it’s kinda unlikely for two unrelated Molinas to live in the same area? Yeah. Do I really need hard statistics to create a headcanon where the principal is Domingo’s sister? Nope. Is it more likely that she’s named after the actress Carmen Molina? Yes. Will this stop me? No.
Anyways welcome Domingo’s sister now, Carmen. Just welcome her and don’t ask too many questions. Because this is just a theory, a film theory.
(Anyway imagine finding out an ex employee of yours that tried to hit on you was apparently a drug kingpin and then finding out he murdered your little brother BEFORE trying to fucking kiss you, I’d commit arson)