Why didn't Jacobs go visit her children in jail?

It wasn't safe to visit her children, and everyone advised her against it.

When I heard that my little ones were in a loathsome jail, my first impulse was to go to them. I was encountering dangers for the sake of freeing them, and must I be the cause of their death? The thought was agonizing. My benefactress tried to soothe me by telling me that my aunt would take good care of the children while they remained in jail. But it added to my pain to think that the good old aunt, who had always been so kind to her sister's orphan children, should be shut up in prison for no other crime than loving them. I suppose my friends feared a reckless movement on my part, knowing, as they did, that my life was bound up in my children. I received a note from my brother William. It was scarcely legible, and ran thus: "Wherever you are, dear sister, I beg of you not to come here. We are all much better off than you are. If you come, you will ruin us all. They would force you to tell where you had been, or they would kill you. Take the advice of your friends; if not for the sake of me and your children, at least for the sake of those you would ruin."