Something that I've noticed is the estimated postmortem interval that was listed for Colleen after her body was found on April 6. I read an article about this case (the article is decades old, so she was still a UID at the time), and according to that article, it was estimated that Colleen had been killed three to ten days before her discovery. I know that estimating time since death is not an exact science, but that entire time window, which is already rather wide, does not match up very well with Colleen's established date of disappearance (which was about nineteen days prior to April 6).
In hindsight, it also looks like the body was in decent-enough shape to where they were able to at least somewhat accurately estimate Colleen's weight and eye color (although they estimated her to have been a bit heavier than her true listed weight, and her eyes were apparently hazel and not brown). This suggests to me that although Colleen was discovered in a decomposed state upon her discovery, the decomposition couldn't have been all that extensive, which, in turn, suggests that she might not have been killed immediately upon her disappearance. I'm still taking the postmortem interval with a grain of salt, considering that the body was buried (which could have preserved the remains, I guess), but these estimates are correct, it looks like she could have actually been alive for as long as sixteen or so days after she had initially gone missing.
I wonder what might have happened to her. I'm not entirely sure that she was truly a Wilder victim. As far as I know, there isn't any concrete evidence linking the two, but I could be mistaken.