Woman Arrested For Murder 53 Years After The crime

From jsonline: For more than 50 years, doubts dogged the memory of little Jeaneen Marie Klokow.
The 7-month-old died at her Sheboygan home in 1957, after her mother said she had fallen from a sofa and hit her head. The official cause of death was listed as an accident, but relatives always suspected worse.
Now, after an extraordinary two-year investigation that was equal parts forensics, historical research and family therapy, Jeaneen's mother has been charged with killing the infant. Prosecutors say it is the oldest case ever charged in Sheboygan County and possibly the state.
Ruby C. Klokow, 74, faces one count of a crime no longer on the books - second-degree murder, or causing death by imminently dangerous conduct "evincing a depraved mind." She was arrested at her home Monday and is being held at the Sheboygan County Jail on $10,000 bail.
The criminal complaint tells the story of Klokow's abusive relationship with her children, recounted by her oldest son and others who remembered her as a mean young mother with a bad temper.
Sheboygan District Attorney Joe DeCecco called it "a sad and tragic situation" that likely would have been addressed much sooner in today's environment of heightened child abuse awareness, mandatory reporting laws and more refined death investigations.
http://www.jsonline.com/news/crime/115394084.html
This will be a hard case to prosecute. And if she is convicted, what would be the punishment be? Do you put her in prison for a crime that happened 53 years ago? If so, what purpose would it serve- it wouldn't be a deterrent and it sounds like this woman had a lot of punishment in her life. but if you don't put her in prison, then you may be allowing her to get away with murder.
A very difficult case.