Nobody's posted on this thread in a while but this case has stuck with me and now that I finally quit lurking and got myself a Websleuths account I figured I should share my theory. Maybe this woman died in an institution or group home... Perhaps she was intentionally murdered, or she could have been accidentally killed by another patient, died of an untreated illness or neglect, the list goes on. Cause of death irregardless, she was probably disposed of by employee(s) of the institution, probably to cover up abuse/neglect on their part. If it's widely thought she was institutionalized, it's a longshot, but plausible. Maybe she was put into an institution as her parents aged and became unable to care for her. If she was as severely disabled as she's thought to be (curious if this is solely because of her facial features or if there's more concrete evidence) than it's likely either her family was involved or she had no family around to notice that she was missing. I personally believe she was never reported missing and was either killed by a family member/caregiver or died in an institution, but that's just my two cents.