If there are children involved, you are married.
Annulments were never meant for those with children.
What in the world are you talking about? I've rarely seen such nonsense. What's even more shocking is that someone upthumbed this post.
One could argue that if you have children, you SHOULD remain together and get the marriage sanated or fixed ... if possible. In some cases it's not possible and the Church MAY under some very strict circuмstances permit you to remain together as brother and sister for the sake of the children.
But, no, it's absolutely not true that "if there are children involved, you are married." There are a thousand scenarios where this is not true. Let's say that a woman divorces her legitimate husband, then shacks up with some other guy and has children with him. They are most certainly not married and cannot be married until her first husband dies and then they marry legitimately. Until such a time, they are most certainly not married, despite the children.
And what is this "Annulments were never meant ..."? You seem to have this notion that annulments are proceedings of some kind that sever the bond between a married couple. They're nothing more than findings of fact.
If you don't know what you're talking about, please refrain from posting.