We don't know yet, Cactus.
Yeah, I dislike that wife, too. Very trashy to bang another guy when your own husband is barely room temp. And I hate her 80's style feathered bangs. Anyway, that little blonde sister is now quite infected, and so they now have to separate her head. No getting around it, no matter how much big sister wails.
During episode two, when they start chopping up the dead guy to use his guts for cammo, my husband was eating dinner. 
Well, she's dead, but I expect the characters to collectively pick up the idiot ball and forget about her. These zombies don't come back so fast, so they might not think of it.
Actually, is it clear that those KILLED by zombies come back if not more or less devoured? The mother in ep. 1 was alive and then infected but not killed, then ran the fever which causes death and zombiehood.
So far the writers have stolen the old out-of-it-in-the-hospital gag while-the-zombie-apocalypse happened (28 Days Later, yeah, I know not zombies, but same setup as this plot device), the back-the-rolling-gate-truck-up-to-the-warehouse wheeze (Dawn of the Dead remake), and the cover-ourselves-in-zombie-gore-so-we-pass trick (the really awful House of the Dead II). And we're also getting way too much "informed attribute" stuff about the main character Grimes being a badass; show us, don't tell us. And they didn't telegraph that Merle was going to cut his hand off much, right, with that toolbox knocked over and conveniently placed? BUT, hey, it's zombies and at least we had a good old-fashioned zombie attack last episode at the end--things were getting way too comfortable in that camping ground.
I haven't read the comics so don't know what to expect, but considering the condition of some of the zombies we've seen (for example, bisected and still dragging itself by the arms in Ep 1), this has to be considered true zombiehood, not infected humans even if it does start with a virus. And heck, there's precedent for that--the brain-eating trioxin zombies of Return of the Living Dead movies aren't supernatural types but might as well be, and same for Resident Evil zombs.
Zombies!!