Razor wire, automated heavy machine guns (used on the N/S Korean boarder), layered mine fields are a plus.
Thermal and motion directed 20mm gun turrets every 1/4 mile will work.
Don’t need a wall. Just two 10’ chain link fences 100 meters apart with warnings (signs and audible/lasers/spots) that between the fences all life is shot to death without regard.
With detection comes 3 levels of warning then she opens up.