I mean she's clearly been smart as hell (by anime standards) during the battle so far and Ash has no Fairies on his team so it's irrelevant.
The other thing is that her strategy seems to be let Togekiss weaken Lucario so Garchomp can finish it, but Garchomp took a huge hit from Sirfetch'd (and it's even harder if the writers remember that Scale Shot lowers defense), and all it has to take on the Steel type Lucario is three attacks Lucario resists and a now-useless support move.
---
""Love" is making a shot to the knees of a target 120 kilometers away using an Aratech sniper rifle with a tri-light scope." HK-47