Agree 100%
I think this is exactly how Mom planned this early on. To me it's obvious. I agree 100% about her activities. But I disagree about Tim's final resting place. I think he is buried out in a deserted area. His Mother drugged him, with something like sleeping pills to knock him out to minimize his pain, strangled him, either dug a hole and buried him, or dumped him in a body of water, maybe Lake Michigan. If Tim is in a body of water, it would be really hard to find him.
Tim is buried somewhere between the parameters of Illinois and Wisconsin. Not able to live with what she did, she killed herself shortly thereafter so that in her unstable mindset, they are together forever in heaven, and no one can change that.
Tim's Mom had this planned for a very long time. The only mystery is exactly where is Tim's body? Sadly, I am 100% sure that he is dead at his Mother's hands.
Satch