News of Adeline's death spread throughout the Delarosa's territory like a domino effect, accelerating the inevitable surrender of her people. Everyone already knew they couldn't win. Thus, her death cemented that truth.
Ultimately, most members were loyal to the Delarosa Household itself and not to an authoritative individual like High Witch Adeline. As such, they were freed of command upon her death and had no aversion to surrendering.
In fact, Adeline's surrendered subordinates even assisted with the aftermath's cleanup.
With the convenience of magic and the effort of several hundred witches, the Delarosa's estate returned to its post-battle state in a matter of minutes, albeit only in appearance for some parts.
After all, Vaan's flames had ripped holes through the main residential building, which had a strong defense against outside attacks.
The ceilings could be patched up, but the materials lost to the flames couldn't be easily replaced.