Thanks for the support, everyone - both in comments and in email. Erica is sending me a book to read, which also got me to thinking about the entire subject, about which I know very little. I ended up doing a bit of research, including reading professional research papers. Very interesting and very enlightening. Some of the results of these studies show that this is one of the hardest addictions/behaviors to break as hoarders typically have no self-awareness of their own problem.
In addition, the research was very interesting in pointing to how this disorder affects children of hoarders, depending upon how old they were when the disorder presented. While I think there were always tendencies always towards the buying/accumulating, my Dad actually had taken away the checkbook and she was on an allowance that was doled out my his mother, as he worked away from home through the week. Looking back on it, I can see that the signs were there even when he was still alive. He came home for the weekends and Friday would be this mad dash to clean and straighten everything up (or stash it) before Dad came home. He died when I was ten, so from that point on, it just fell apart. So I had ten years of normalcy - other than the obvious dysfunction in my parents' relationship. By the time my sister came along when I was almost 16, it was in full phase. My sister has never known anything different.
Anyway, as Leslie pointed out, I spent the most of the day feeling a lot of the old feelings. I did get some insight and relief by doing do a bit of studying and my experience and results are pretty darn typical. Oh, and the most given advice for professionals? Treat children of hoarders like they were children of alcoholics - their outcomes are pretty similar.
I came home from the office, changed, spent some time journaling and reading literature. I determined that my best course of action was to stay focused on the task at hand - finding the leak. I could not/would not be deterred. It was my best chance of maintaining my serenity and not going off on any tangents about what other's should be doing. My opinions are to be kept to myself, other than in matters of determining the cause of the leak.
After being assured that they had checked everywhere, including under the sink and no leak was to be found, the leak was under the sink. I did not get it fixed, as I don't have the right tools, but I will call the plumber to come out tomorrow. For as long as this has been leaking, one more day isn't going to make things that much worse. Neither Mother or my sister is available at all tomorrow, so I will come out and meet the plumber and hopefully the insurance adjuster at the same time.
I did manage to stay in my solution. There was plenty of talk about why things were the way they were, but I didn't allow myself to comment or voice an opinion or call bullshit. I just let it be and stayed focused on my need for a solution to the only problem that was mine to solve. So I am happy with how I got through the day - other than by eating everything that I was fast enough to run down. But tomorrow is another day. I cannot expect perfection of myself or anyone else. I did the best that I could.