There are some very strange things about this case... that she had a fight with her sister, who told her that if she left, she would no longer be her sister and that she shouldn't come back... and that she had been very close to her sister and that her sister had started looking for her... Was this the same sister she had the fight with?
She also had no reason to hide and live alone, but her children were placed in foster care after her disappearance, so it seems she was their primary guardian... Not wanting to raise your children seems like a compelling reason to remain in hiding...
The scenario that makes the most sense to me is that she left voluntarily... She discovered her sister was trying to track her down, felt she had burned her bridges there, and didn't want to raise her children, so she tried to minimize her chances of being discovered...
The three things that strike me as odd are:
That she didn't go with Charles Wegman.
That Wegman was known to at least one FBI agent who saw him.
That he didn't have a driver's license or a marriage certificate. I know some women who burn out about a decade after their disappearance... they never learned to drive... but relied on their husbands for transportation... so I find it odd that she lacks both... she could have been driving illegally or had a fake license (I've heard that was easier before), and also not married or married under a fake name... but it's still odd...
I don't think the lack of Social Security is odd... maybe she just passed away before having a chance to access it...
whatever it is
Rest in peace