I say focus on Wildshaping, or arguably Shapeshift variant. Have her turn into something big and touch (treants are popular, and I think there are PrCs that make that happen faster), be willing to sacrifice a little bit of casting for some combat boosts (e.g., wildshaping buffing PrCs, Fist of the Forest, maybe), and go to town.
The other thing you might consider is something like Combat Reflexes + Stand Still to help her "draw aggro." Overall, though, being a giant bear/tree/whatever might do a good job of that.
One other possibility might be to do a different take on the whole angle. Druids are the most complicated class in the game. They have all the headaches of being a spellcaster, plus all the headaches of polymorph, plus all the headaches of a minion and potentially of a summoner. You might want to go more the Bear Warrior or Wildshape Ranger route. They both feel druidy, but don't have quite the mechanical burden (and can be QUITE tough), which feels prohibitive for me, especially for a 1-shot. I'm a daft hand at 3.5 D&D, but I'd usually shy away from playing a 10th level Druid for only a couple of sessions.
If you want, I could post a build later on, or a sketch of one.