Monday Madness ~ Who is Betty Boberg?

My great-great-great-grandfather Carl Tolf "was lying dead at #5926 Sangamon St...on the 18th day of March A.D. 1890...from heart disease" as documented on a coroner's report. There is only one witness at the hearing; her name is Betty Boberg.

Betty lived at the Sangamon St address with her husband August and their two children. The coroner's report says Carl lived there too. Not sure if that's correct; his wife and at least four of his children lived in Batavia Illinois.

I followed Betty and her family through many census records, city directories, and the like. Her obituary says Betty (Tolf) Boberg. But her father's name was Turse Johns. Her mother's name was Mathilda Tolf, but I can find no connection (as of yet) between Mathilda and Carl.

Could Betty have been a niece somehow? A second cousin perhaps? I can't find any evidence of a relationship between Carl's surviving family members and Betty's family. I haven't found anything in the Swedish parish records that connects the two families.

I'll continue to watch for clues as to Betty's identity, but for now I'll just have to wonder.