Shaw leaves us hanging at the end of the play, with Eliza having walked out on Higgins but not having yet agreed to marry Freddy. Shaw then goes on to explain in an afterword exactly what happened. Eliza does not marry Higgins. He is too old for her, and more importantly, he would always put his mother and his work ahead of her. Eliza, Shaw says, wants a companionate marriage in which she is the primary object of her husband's attention and affection.

That leaves Freddy, who is young, handsome, a gentleman, and adores her. He is weak and Eliza is strong, which Shaw argues is a good basis for a marriage.

The Hollywood movie version has Eliza and Doolittle falling into each other's arms at the end. I believe that is the wrong ending. I would, however, have Eliza shown agreeing to marry Freddie—and I would have Doolittle shown utterly astonished that she never again runs his errands for him. Even though we know his mother will fill in, it would be a satisfying ending for Doolittle to start to realize that Eliza really is fully a human being who ought to be treated with some dignity.

Another option is to go completely wild and envision Doolittle's mother dying and Doolittle finding out he is a pauper who has to come to the now wealthy Eliza, Freddy's wife, for help. Maybe he could become her butler. It would be satisfying to see the tables turned.

Of course, you need to think about the play and come up with your own most satisfying ending.