I don't know what parent would NOT WANT their child to become a religious. That, to me, is just unbelievably sad.
I am sort of in this category. It's not that I would NOT want my child to be a religious, but I'll be honest... If he does have a vocation, I would be much more relieved as a mother if he is called to be a humble, barely noticed, maybe even underestimated, little porter out at some monastery somewhere than if he is called to a more public and pressured position of priesthood. I have girl friends who have "rose-colored glasses" over visions of sons as priests and while I understand the sentiment and know we need dreams of magnanimity... from the protective mother's perspective of wanting him to have the straightest, sweetest journey to heaven possible, the humble porter is the way to go.
But I keep that to myself and won't ever mention it to him because I know it's a bit selfish. There are a few signs (like my son having delays and learning disabilities that would probably prevent priesthood) that show that God might humor my mother's heart. He has humored me in a very special way once before. But we'll see. He may marry, he may live at home forever, he may indeed become a priest, we have no idea what to expect.