Hurley is Libby's constant, her back-story is still weird, her husbands name was Dave, he died. What if Dave (Libby's Dave) worked on stuff like that of Daniel’s time travel stuff, or worked with him even and the same thing happened to him and Libby. He died because he didn’t know about the constant. Libby in her crazy time travel jump stuff, got institutionalized, especially after Dave died, and when she did she ran into Hurley in the institute and on the island, so without knowing it, she had her constant. The only problem I can find is how come she didn’t black out and stuff; although after she found her constant she wouldn’t have done that, just like Desmond. I like this theory because it answers who her husband was, why she was in the institute, and why she was so attached to Hurley.