Try this:
// for graph builder
gb = Graph Builder(
Show Control Panel( 0 ),
Size( 3000, 3000 ), // <<<<<<<<<<<<<<<
Fit to Window( "Off" ), // <<<<<<<<<<<<<<<<<
Variables( X( :height ), Y( :weight ), Overlay( :sex ) ),
Elements( Points( X, Y, Legend( 1 ) ), Smoother( X, Y, Legend( 2 ) ) )
);
gb<<savepicture("$desktop/gb.png");
This works for Graph Builder when the screen is locked and can make huge graphs; you'll need to bump up the font sizes and line widths too if you go as big as shown above. Most other platforms don't have the FitToWindow behavior, so just resizing the graph is sufficient.
I'm not sure how windows implements the locked screen behavior, sometimes referred to as headless. Discussion , I'm not recommending installing any third party software.
Craige