Because her mental state is compromised. It was compromised before she wrote the notes. How do we know that? Because she murdered multiple newborns.
When somebody has an unstable mental state, they don't have a clear conscious stream of thought.
"There are no words. Kill myself right now. Fear. Panic." This not imply innocence. This implies that she is scared, panicking and has no words and wants to kill herself because she has been caught, the walls are crashing down and she knows she is never getting out of prison. Who wouldnt want to kill themselves. She may very well be deeply upset and traumatised by her own actions, further demonstrating her unstable state of mind. She kills babies and then feels guilt and then goes and does it again. If that is not the hallmark of someone in an unstable mental state then I dont know what is.
"I haven't done anything wrong. Police investigation. Slander. Discrimination. Victimisation"
This is denial. This is her again demonstrating her unstable mental state by not being able to acknowledge that what she has done is wrong. Compromised mental state further evidenced by her contradicting line on another note: "I killed them. I did this". She cannot produce a single clear, consistent thought. This quote is purely her trying to convince herself that this is not her fault. The 15 whole life orders suggest otherwise.
"If she felt bad about murdering babies, why keep doing it?" ????? Because she is mentally unwell. It really is that simple.
"If she killed the babies, she has done something wrong, and she clearly knows it is wrong, or she wouldn't want to kill herself. It can't be that she feels scared about being caught; that doesn't fit with "I have done nothing wrong."
It cant be that she is scared about being caught? Are you being serious? Do you seriously think criminals who know they have committed a crime, are not scared of being caught? Have you ever met anybody that has been in prison or knows they are going to prosecuted? 9 times out of 10 they are terrified, even for heinous crimes that they chose to commit. She is a human being with human emotion. She got found out, she got scared. She tries to draft her innocence on a post it note by saying she hasn't done anything wrong. The poor me act. And here you are buying into it. If I knew I had murdered multiple newborns and was going to be imprisoned for life I would want to kill myself as well.
One statement takes credence over the rest of the note because she explicitly admits to killing them. I know this is not to be taken at face value given everything else she wrote; it call contradicts each other and cancels itself out. Thats when you look at the smaller picture. When you look at the bigger picture, you see a woman in a broken down mental state, writing that she killed them, she did this, also writing that she is innocent and it is just slander. It is just evidence that she was never in any mental state to ever be looking after them. The bigger picture reflects that she doesn't know what she's thinking, and ultimately makes her discredited because of it. You say why are the confessions taken at face value but her claims of innocence are not. If someone kills someone else and says "yeah I killed them, oh wait no I didn't" are you going to feel more inclined to believe that they didnt? You cant take those sorts of statements back once you have said them.
Im in no way claiming the notes specifically should be taken as a genuine confession, due to her obvious compromised mental state. It is just that they chaotic nature of them, the conflicting statements, the way they are written so fast, angrily, and emotionally should all be taken into account when looking at the bigger picture of her mental state. I understand you think she may be writing what others think, I.e. 'I killed them because im not good enough' being a reflection of what others may think of her or her own thoughts about her failings in her job, but it ultimately boils down to: she wouldnt have been arrested, charged and handed 15 whole life orders had there not been sufficient evidence against her to evidence that she killed them. Whether the notes are confessional or not is trivial to seeing that she is guilty.