don't you glue and screw a 3/8 piece of teak about 6 inches square with rounded over edges on the inside and outside of the head door at the height you need and screw a foldable mast step to it. She could step right into the bunk with her left foot facing in and her right foot if she went in back words. The door should be plenty strong enough to support the weight. Fold it up when it's not in use. Very clean. I love those things. You can get them in SS or bronze.