Is sending fatwas to a girl with whom a young man is not in contact – after a previous relationship between them – considered forbidden?

There is no objection to sending fatwas to your fiancée, as it is a dissemination of knowledge and goodness, for the Prophet, peace and blessings be upon him, said: "The one who points to good is like the one who does it." You both did well by stopping the impermissible communication between you, so remain steadfast in that until the legitimate marriage takes place.