Chapt 7, Part 4. Breed with a Smitten Dragon.
In order to get Smitten back to adventures quickly, breed Smitten with a solid pink dragon (such as Virtue, Naga, Kitsune, Black Swan). The only outcome is a Fire dragon
update: fire was the only outcome from a "source", now proved to be inaccurate
so sorry to those who fell behind due to this!