1. Put more focus on binds than status ailments. If you inflict too many status ailments on her in the beginning, like panic or poison, she'll become immune to them. In the first half of the battle, cripple her with binds.
2. Adding onto this, utilize as many of your bind-inflicting party members as possible, like Pugilists, Harbingers, and Rovers. Max out their status infliction and bind rates as much as you can. The pugilists in particular are a Godsend if you need to inflict binds. Binds are important in preventing her from using her powerful attacks like Earth's Heal and Rage Vent, both of which are a pain in the ass to deal with.
3. Save panicking her for when she's lost more than half of her HP. If you try to inflict panic on her too many times in the beginning, she'll become immune to panic. Panic is the best ailment to inflict on her, especially when she's close to losing, because she'll hurt herself more times than not, and you'll have less problem with her becoming immune to it later.
4. If you have a Brouni in your party, like a shaman or a botanist, make use of Aegis Shield! If you didn't get to inflict successful binds on Dryad in the beginning, she will one-shot your party with Rage Vent. Aegis Shield nullifies all attacks for one turn, so you can save yourself whenever Dryad tries to use Rage Vent on you the first time.
5. Black Mist from an Earthlain party member helps too, like from a Harbinger. This decreases an enemy's resistance to binds and ailments. But again, I'd recommend using this for later in the battle, as she becomes immune to certain status ailments if hit with them too many times.
I hope this helps somewhat!