The opening panel. It was an off-putting image for me and the none of the words make sense to me other than referring to the title somehow? It tells me this might not be going in a direction I like. I powered through it though.
The switch from the hardworking character redemption kind of plot to the yandere, secret-axe murderer plot. The transitions were jarring for me because the story suddenly went from believable to not believable. The videoing the manager with her phone trick didn't feel very clever to me, and I have no idea how/why she managed to kill three people and apparently take their house. Any kind of foreshadowing or even saying "Oh she had some violent boyfriends and learned some self-defense/made her crazy" could have made it better for me.
The ending. Again, I couldn't quite believe the ending with the heads. Additionally, I have a hard time understanding the MC's goal. Money is an easy goal to understand. Everyone needs money for something. Her goal at the end of the chapter, build a fortress to "protect" the little girl, does not make sense in the fact that no antagonists/people looking for the girl have been introduced yet (no, I am not counting the Missing poster. I need something concrete and threatening).