You're right, Superman, it jumps out at you the moment you see the art. The girl is drawn even more realistically--and sympathetically--than Ellen Dolan and The Spirit, the only other non-caricatures. The girl's poses in the last three panels of page 3 are so lively and believable that you can imagine the artist thinking, "At last! I get to draw a real person!" I wonder who the artist is. This doesn't have the Lou Fine vibe of many strips from this period.
Link to the book:
Spirit Section 1944-11-19 (Philadelphia Record)