Tealgrove, I like how you think. I feel strongly there is foul play here.
Not only do I feel she wouldn't leave her son, but after looking at what I could on her Facebook, she would not put her parents through this he!!
If I may, I want to share a little bit about domestic violence. My sister was in a relationship, and it was a controlling abusive relationship. In the end her and I had to work out this deal, that one sister paid for the moving van while the other sister, me, waited around the corner for the boyfriend to go to work, I zoomed in with the truck and we loaded as fast as we could. It was all in cahoots.
Although I love my sister deeply, let's fast forward to 2 years later. Again she's in another abusive relationship. Again ssisters get in cahoots to get her out of it. We arrange for me to pick a fight with her so it looks like we're at odds, can't stand each other, she made it look like she wouldn't search out me for help. Then the next morning my husband and my son-in-law travel 3 1/2 hours to her town wait around the corner, again waiting for the boyfriend to go to work, and as soon as he did they backed in our truck and they loaded up. He never contacted me, he never had anything to do with me, because he knew that my sister and I were at odds.
Point of my story is, if she, Heidi was to run off on her own, I would actually think that her and her mother could easily go into cahoots, she go into hiding. Somehow the grandmother gets a hold of the grandson, and they all meet up somewhere later.
The personality of this woman does not seem like one that would put her parents on the risk of either of them having a heart attack over this.
I feel it's foul play, but not at Heidi's doing.