I think Charlotte Church's voice is perfect for this piece. Often, it is sung by women or boy sopranos. I think neither capture the lament of the young Mary, and when Charlotte sang this, in her more popular days, she was also barely a teenager. She released the track album "Dream a Dream", an album of Christmas carols in 2000 when she was just fourteen. Here are the lyrics.
I remember reading somewhere that the nativity story anticipates the crucifixion. The young innocent Jesus faces death, even at birth. And this cloud follows him to his actual death at Easter, still and always innocent.
We should just be thankful we had him for those few years, when in a flurry of responsibility, he disseminated so much of his message to us and his disciples.