Her death by carbon monoxide poisoning might have been unintentional on the part of her abductor(s), but it could certainly qualify as a federal case of first degree murder, since it occurred during the commission and as a consequence of the interstate kidnapping.
It was NOT an accident.
Although this case differs in some ways to those murders of children connected to the "Oakland County (Michigan) Child Killer (OCCK), there are some strong similarities which seem to connect it.
Like the 4 generally accepted OCCK victims, Jane was abducted from Oakland County in 1976. She was young, and was missing for several days before being found dead.
Rather than focusing on the "difference" of Jane being found near Cincinnati, Ohio, perhaps she could be a key factor linking the other victims to a perpetrator/ perpetrators connected to Cincinnati.
One strange connecting factor in the deaths of the other Oakland County children is that they were taken somewhere, held for a time, and carefully groomed or bathed before being placed where found in Oakland County, Michigan.
Is it possible that all of these children were taken into Ohio, following their abductions? Perhaps Janey's death by Carbon Monoxide poisoning in the car's trunk broke the pattern and caused the abductor to discard her immediately.