Hmm, well I'm not sure how you'll feel about High Wizardry (the third book) because it mainly stars Nita's sister, Dairine, in the title role, and the focus is on technology and life-- how many varieties of life there are, how alive technology can be, etc. It's better than Deep Wizardry and the 4th book, but the 5th and 6th books are very, very good in my opinion. I love this series.