"Raphtalia was not found by Naofumi by coincidence. When the queen was informed about the summoning, she was pissed, and she expected the church to act against the Shield Hero, which would worsen her job even more, and she gave some orders to the shadows.
You may have noticed from the start of the story that Naofumi gets no support from anyone, a few days pass and he earns too little, however, one character took initiative to help him, who is it? The Slave Merchant. don't you think it's strange for that guy to reach Naofumi out of his own accord and suddenly have a convenient "tool" that was just enough for Naofumi's poor situation?
That's right, one of the orders was the Queen asking the slave merchant to somehow support the Shield Hero, because she knew that the Shield would not receive proper support, and that the shield can't work with no attack. Raphtalia was the cheap tool the Slave Merchant could spare of as support, but things went much better than he expected. "
Considering that information, maybe, after learning about the escape of the Shield and Spear Heroes, the Queen will help Naofumi and put Raphtalia on his path, somehow... I have faith ..!