Thank you so much for not giving up on Kathleen's case and going above and beyond to help provide big clues as to what might have happened and why nothing was making sense - LE's statements and subsequent silence, why no updates, why no evidence of foul play, etc, and eventually why the silence and acceptance for family. It's very possible that they knew things all along that we didn't.
As a recovered alcoholic, all the pieces started to fall into place with the information you found, at least for me. Out of respect for her family I won't go into many speculative details because I really don't know if her record had anything to do with what happened, but I will just say that I personally had one really bad incident in which I had every intention of going to a family event but of course, had to stop at the liquor store because, well, because I needed it. I drank quite a bit in the parking lot and then kept drinking from the open bottle with me in the car, and (horribly ashamed and guilty about this) drove about 30 minutes before getting completely disoriented and ending up in the middle of nowhere, lost. I finally found a parking lot at an abandoned strip mall and pulled in there to sleep it off. Anything really could have happened to me, or worst I could have hurt someone else.
I was firmly in the foul play camp, but now, I think suicide is possible, but that it is highly probable that a combination of circumstances, coincidences and mishaps led to her tragic death. My heart aches for her no matter what happened; there but for the grace of God go I.
Prayers for her friends and families. I am not sure they will ever feel closure over this no matter what.
Edited to add:
@Boston Corbett - I too would use the term "death by misadventure" to describe what might have happened to Kathleen, regardless of what the legal definition of it is. I also heard it used in the bizarre Elisa Lam case (woman drowned in water tanks atop hotel roof) and think it definitely could apply here.