She can be recruited at the room above the Loanne's Castle Storage.
Therese has three decent statuses, Dexterity(22), Speed(23) and Magic(19).
This gears her to the Dexterity alligned weapons(Rapier, Dagger, Bow and Gun)
Her magic is quite high, making her a decent mage also. She comes with the powerful Eastern Bow.
Therese will come out handy, but Liz, Sara, Aisha and Claudia will outmatch Therese with their higher Dexterity and Speed when they get their Cosplay items.