I'm thinking about using an invite for the dryad, but first I want to make sure I understood her power right.

While she stays at your inn, the wild pets will inhabit the free dens at the very next cycle.

So does that mean she summons pets to the dens or is she just calling roaming pets back to the dens?

Right now my map is rather empty so I would like it when new pets would appear, though if her power works the 2nd way then she would be pretty much useless for that.

On that note if she doesn't call forth new pets will the magicians of the beasts (Dragon Magician, Gryphon Magician ect.) do so? Or will they also just work when the dens are inhabited naturally? (which takes 32 hours after you catched the pet of that den right?)

The dryad summons new pets to the free dens. In RPG terms, she increases spawn rate.

The Magicians don't make the new pets inhabit the dens faster (the spawn time remains 32 hours, you're right). They only affect the species of these pets.

Ahh thanky you this was exactly the information I was looking for. ^_^