I think he'll be surprised at how it turns out. After all, the thing to keep in mind about Dorothea is that she is Saint Teresa of Avila without the opportunity to be Teresa, without the chance to live the epic life that fits her nature. As Eliot says in the prelude,
Many Theresas have been born who found for themselves no epic life wherein there was a constant unfolding of far-resonant action; perhaps only a life of mistakes, the offspring of a certain spiritual grandeur ill-matched with the meanness of opportunity; perhaps a tragic failure which found no sacred poet and sank unwept into oblivion. With dim lights and tangled circumstance they tried to shape their thought and deed in noble agreement; but after all, to common eyes their struggles seemed mere inconsistency and formlessness; for these later-born Theresas were helped by no coherent social faith and order which could perform the function of knowledge for the ardently willing soul. Their ardor alternated between a vague ideal and the common yearning of womanhood; so that the one was disapproved as extravagance, and the other condemned as a lapse.
And I think Eliot really should be taken at face-value here: Dorothea is intended to be like the Great Reformer of Carmel, but without a Carmel to reform; like the Great Foundress -- but, as Eliot says later, "a foundress of nothing." Wasted energy. Although, of course, one of the great things about Eliot's treatment is the question of how wasted the energy really is in the end, despite its lack of "far-resonant action." Dorothea is a blundering Teresa; because she is full of mistakes and lack of opportunity, her spiritual grandeur is never given full scope. But even within the narrow confines of Middlemarch a blundering, hindered Teresa may still have something of that Teresa grandeur.