Unfortunately, a browser won’t let a program such as MyCurator re-size the window once it is open – a security issue I guess. What you can do is change the default size of the window, especially if you normally will be editing. You can do this by editing the bookmarklet.
In the URL field will be a long string of code. Go to the end with the End key, then use the arrow to head back to the middle. When you see width=xxx,height=yyy you can change the xxx and yyy to larger numbers. For instance, 1200 width and 800 height should be fairly large on a normal monitor.
You could edit the title to Get It Large and then drag another bookmarklet from the Get It menu and title it Get It Small. Now you could use Get It Large for editing and Get It Small for just grabbing content.