She ran away from the courthouse!
First, she went to Wisconsin. She was with some friends for a few days and then left by herself, presumably for Colorado.
She was probably resourceful and had some connections.
(Sorry I may not have all the facts correct. I'm going off my memory) They were looking for her and she was reported missing.
When she turned 18, law enforcement discontinued their investigation into her disappearance. However, I don't think it was a very serious investigation. LE did not go out of their way to locate runaways back then. Obviously, she was in Colorado in August and LE probably could have located her then, but I'm sure they didn't make an effort.
Witnesses reported seeing Sherri Ann Jarvis in two separate locations on the night she died.
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