I've found that occasionally flipping things in English and German from always to never makes for the better translation. This is much closer to how this would be phrased in English, from what I've heard of a lifetime (40+ years) of "religious speak"... I suppose you could also phrase it "Nothing happens outside of the will..." or even clarify "...and of His Mother, Mary" if you believe that this wouldn't be clear to your audience today.
EDIT: I also believe that something like "Nothing happens outside of God's Providence". "Providence" is a little bit of an old-fashioned term in English, and I think the author I remember using the term the most consistently is L.M. Montgomery (author of "Anne of Green Gables" and many others). Providence is sometimes used for a "blessed coincidence" or, in the parlance of Bob Ross "happy accident" but in older works it also definitely has the meaning of being something like a shield of God's, which doesn't necessarily keep bad things from happening, but often lessens the blow, or allows something good to come out of a bad situation for those who call on Him in prayer. Theologically, it gets a little tricky, because in general, because Mary is not God, but especially in the Catholic and Orthodox Churches, we believe the saints can hear .us and intercede (pray) for us. As Mary is so important to Christianity, it is very common that she is called upon to pray for us.