Dutiful

This girl was always good and dutiful.

He was dutiful.

Layla was a dutiful caretaker.

Robert looked like a dutiful student.

Thanks to Robert's tutoring, Sandra looks like a dutiful student now.

We had a prince: it was Aeneas, the noblest warrior, the most just lord, dutiful, virtuous, and good.

Ralph was a dutiful child, and took the trash out without being told.

And when blondes and beautiful are multiple / They become so dull and dutiful