Sure Fairy Maids only focuses on attacking vanilla mobs like the Players and Iron Golems, what if they can interact with modded mobs?

Fairy Maids can Seize Modded mobs:
Bunfungus (Alex's Mobs) - https://modrinth.com/mod/alexs-mobs

Fairy Maids that will run away from Modded mob:
Reimu Hakurei (Youkai's Homecoming)

• This represents how Reimu is too strong against the lesser fairies, so you shouldn't mess with her or come here youkaified as well or else she will turn you into a pile of Power points.
  https://modrinth.com/mod/youkaishomecoming/versions

Foliaath (Mowzie's Mobs)

• Fairy Maids did not want to go near a Hungry Foliaath Plant as those monster plants loved to eat zombies.
  https://www.curseforge.com/minecraft/mc-mods/mowzies-mobs

Sculk infected mobs (Sculk Horde)

• This represents how they're scared of the Sculk apocalypse. due to their fear how their fellow Zombies and Skeletons became infected by the sculk, they will run away
  https://modrinth.com/mod/sculk-horde