You are changing the relationships by changing Savannah Phillips’ parents. I think that is a false simplification of the graph that should never be done.
You can run through the tree and make not visible the nodes that you want to hide. It isn’t clear to me exactly what rules you want to follow, but you can figure it out. At the end of that transaction the TreeLayout will automatically produce your desired layout.
Oh, sorry, I dont want change relationships or hide/show nodes.
I Want better lines that on first image: without Bolder/lighter places (“merge” multiple lines to one) and have a first child at center position after parent .Without that odd “intersections” like this:
I suppose you could have a common width on all of the first children. That requires an override of a TreeLayout method, probably TreeLayout | GoJS API that modifies the LayoutVertex.width and focus.