How is the end of the play the beginning of a new life for Eliza?

Liza has gained the skills that Professor Higgins has taught her. Although he tells her he likes the woman she has now become, she says goodbye to him. Shaw in his epilogue hypothesizes how she might end up, but the open end of the play is visibly demonstrated in the musical My Fair Lady when that production chooses to put her back in the Higgins residence, although perhaps in a more respected role.