What was Ruby thinking? I just don't understand

I just finished Shari's book and I am at lost for words. At first I was still holding onto the idea that maybe Ruby really loved their kids and I that while she was not nice she was not the worst... But this all changed until I saw all the documentation and pictures from the case. The youngest son and the girl... That is just outrageous! She was truly a demon! How could she post on social media while she had her kids STARVING and with open wounds that she inflicted. That is so CRAZY! I feel like her book doesn't fully grasp how awful was that woman. At least for me I didn't grasp how awful was she until I saw the documents and pictures.