I'm remembering how Our Lord said, "I am the Vine; you are the branches. If you remain in Me, you will bear much fruit."
I've done some thinking about how "fruitfulness" differs from "efficiency". Fruitfulness has to do with the inner, organic nature of a thing: Jesus talks also about how only the good tree bears good fruit.
So it seems we have a guarantee that Sr. Antonia's life will have been fruitful, since she was acting within her relationship with Our Lord, who is the source of all that is is truly good and truly lasting.
Good, lasting results with these "lost souls"? I'd bet my right arm up to the shoulder on that. I'd bet my life.
Hence my answer.
Some of my typos, I don't know how they happen. They are bigger and more complicated than the ordinary typos!