Forgiving an Act of Love

A mother, suffering from depression, drowns her children because she fears they are possessed.  Should she be forgiven?  She murdered her children.  Why wouldn't we lock up a murderer?  Of course, she did hear voices in her head telling her to do it.  She did kill them to save them from the demonic spirits.  Does this matter?  Yes.  I believe it does.  The woman was going mad with the thought of her children hosting such dark spirits.  The voices provided an answer for her, a way to escape the horrors.  Though she did create horrors rather than escape them, she believed that she was doing what she had to.  She "saved" her children in the only way she saw fit.  She loved them.  She can't be denied forgiveness for something that she wasn't even mentally sound in committing.