Criminal responsability and post partum psychosis

[OneHolyCow]

Horrible story and it's been haunting me all day. So here's link: Woman jailed after throwing baby down rubbish shute
There is not a lot of information in the story but nevertheless.. how does this work out? If she was psychotic, she would not be criminally responsible, right? Wrong?
I do see that she inflicted terrible injuries on her child but I just feel confused as I do not see how anybody might benefit from her spending time in jail.
Can somebody explain the legal reasoning here?

I have no idea on the legal reasoning I'm at a bit of a loss to the outcome as well.

Surely as she has been diagnosed with pnp she is guilty but with diminished responsibility.

Such a sad story for both baby and mother. I can't imagine having to live with the guilt of harming your own child.

I'm pretty sure that diminished responsibility is only a defence to murder (allowing murder to be reduced to manslaughter due to diminished responsibility). And I thought that defendants generally tried to avoid a defence of insanity (which is a defence for other crimes) since it allows the judge the discretion to effectively lock away the defendant in a secure mental hospital indefinitely to a much greater extent than a guilty conviction allows the judge to sentence them to prison.

It is an horrific tragedy. I can't imagine what it would be like to live with having done that to your child or to grow up knowing your mother did that to you.