I'm aware of who you are referring to, but I've never noticed that part of the story. Do you have a reference for this?
http://www.plainsite.org/dockets/index.html?id=1212890
direct quote from above reference:
"Shortly after he became a fugitive, Floyd developed a relationship with Linda Williams. When they met, Linda Williams had a daughter named Sharon. In 1974, Floyd took Sharon with him after Linda Williams refused to marry him. During Sharon's childhood, Floyd and Sharon lived together as father and daughter in several states. "
I found the "Linda" reference I had found in an appeal document. I read it on the boards under the Sharon Marshall thread also but don't remember who said it or their source, but its 5 whole threads long and really...well, someone who was involved with the threads could find it faster.
Floyd had tight ties to Chicago, his mother lived and died there and is buried there.
Of course, he is a pathological liar, who knows how he really got her, however it is very interesting and maybe worth looking into.
I know there was a theory of a baby snatching ring in the Midwest floating around...but I have not seen any evidence to support or debunk it.