Isaiah and the prophetess

Isaiah 8:3-4 - Then I went to the prophetess, and she conceived and gave birth to a son. And the LORD said to me, "Name him Maher-Shalal-Hash-Baz. Before the boy knows how to say 'My father' or 'My mother,' the wealth of Damascus and the plunder of Samaria will be carried off by the king of Assyria."

I wonder if God told Isaiah to go to the prophetess in order to have a son. I have the feeling that he did because of the name he was told to give the boy and because of the symbol that the boy was to be.

I wonder if God had told the prophetess about his plan for her and Isaiah. I wonder if she would have been surprised if she hadn't been forewarned.

I wonder if Isaiah and the prophetess were considered husband and wife from this point on.