Conversely, Lizzie's younger sister, Mika, willingly kills walkers, but her compassion for others prevents her from taking the life of another human being.

In the episode "Internment", when some infected residents succumb to the virus and reanimate, Lizzie rescues Glenn from a walker by leading it away.

She and Mika carry Rick's baby daughter Judith and rescue Tyreese from two of the Governor's soldiers – shooting Tara's girlfriend Alisha in the head.

Lizzie kills a group of rabbits, and during a walker attack she covers Judith's mouth to try to stop her from crying but nearly smothers the baby.

Lizzie shows great distress when walkers are killed and Mika is unwilling to toughen up and become hardened, due to her compassion for others.

Carol and Tyreese come back to the farmhouse after gathering food in the woods and they see that Lizzie has stabbed Mika to death and plans to do the same to Judith.

In the mid-season premiere "What Happened and What's Going On", Lizzie and Mika appear as hallucinations, along with Beth Greene, Bob Stookey and The Governor, in Tyreese's mind as he is dying from a walker bite.

When Tyreese is bleeding out in the car he sees Lizzie, Mika, Beth and Bob once more; he decides that he wants to let go and join them, and dies peacefully.

[2] Paul Vigna of the Wall Street Journal commented on the cynicism of the episode "The Grove", saying, "Of all the sick, demented things that have happened in the zombie apocalypse on The Walking Dead, it's hard to imagine any as shocking and sad as seeing insane little Lizzie standing over the sister she just stabbed to death, no concept of what she'd just done, fully expecting her to 'come back.'

"[3] Noel Murray of Rolling Stone ranked Lizzie Samuels 25th in a list of 30 best Walking Dead characters, saying, "no one’s been sickened as much as Brighton Sharbino's Lizzie, an adolescent girl so confused about life and death that she gave walkers names … and then murdered her own sister in order to prove that being undead isn't so bad.

More terrifying than any zombie, this kid was a sweet-faced, sharp-fanged rebuke to any hope that the rising generation might make the future brighter.