"You do not understand the dangers that you may face," he said carefully. She didn't understand because he'd not wanted to show that side of himself to her. Parts of it she may have seen, but the piece that was revealed moments ago when he killed Barbas? It was rare he ever let anyone see that side of him, even Malachi.
"Angels, demons, and individuals from both sides of heaven and hell will come for you. Heaven wishes to see the child destroyed and not be given the chance to take on the prophecy and your life will mean nothing to them. Hell wants to use it to their purposes. They will kill Malachi and use this child. As it stands, it will be a mortal dhampir child but the moment something happens to Malachi the power will pass."
If Barbas was aware of the conception then he wasn't alone in that. He was simply a warning and his death would be well known in the pit very soon. Azazeal needed to contact Castiel to discuss this as soon as he left with Viktoria.
"Someone could enter the prison disguised as a resident. It will be impossible for you to know until it is too late. Your life may be here, but your safety and the child's safety must require you to leave it for a time."
Would he force her? No, probably not because he knew what would happen if he did. Instead he had to help her understand the severity of the situation.