This mindset of doing the right thing by feeling compassion, no matter what the person has done, is dangerous. It minimises their actions, it normalises their actions, by attributing then to MH problems it tarnishes everyone else who has those problems, and most of all it brushes aside the real victims by making out that these monsters are also victims.
She was reported by her neighbours and family.
She had all of her children in care at one stage or another.
She was compos mentis enough to google 'how to cover bruises' rather that get help.
This wasn't a one off action, instantly regretted and help sought; she systematically best this child to death whilst he was already ill over a period of three days. His body had over 40 separate injuries. At any stage she could have got help for him, instead she was in the internet posting messages on Facebook.
Some people are monsters. Are you going to excuse the Wests, Brady, Hindley, et all? Where does it end? Does your heart bleed for rapists, murderers, abusers, the man who kills his wife because she nagged him?
The only person who deserves compassion is Mikaeel. And his siblings, who must have been terrified.