I didn't know that the two homes were so close to each other, so yes it's very possible Brent or the son went over there.
I'm thinking, JMW had that important review meeting at the hospital for which she had to prepare all weekend, as was stated in an article. At the same time, she and her husband had a fight the night before.
April 8th is a Sunday. Preparations for the hospital review, a fight, the packing, her MS, where to go with her stuff.....that's a whole lot of pressure. I can see that she was totally overwhelmed. Also when you have your stuff in boxes and bins, it hits home that your home isn't home anymore, the security and comfort is gone. She wanted to leave, either her decision or his (though he says he didn't ask for a divorce or for her to move out). After the fight (and evidently some ongoing marital tension, and possibly an affair involved) she may have perceived that the marriage was over.
She may have been done with it all, just too much o deal with.
Took off in the Tahoe, after shooing her daughter out of the house .....
I'm now leaning to self harm.....her search for peace after all this pressure and turmoil. So very sad if that's the case.