In this game, written for the author's hot-spring loving wife, you explore an expansive wilderness region with a hot spring, wild animals, a friendly old NPC, and beautiful descriptions of nature.
One of my favorite games of all time is Suzanne Britton's novel-length Worlds Apart sci-fi. She specifically cites this game and Sunset over Savannah (a game focusing on a beach and nature) as being an inspiration to her. Having played the two games, I really see how Worlds Apart took inspiration from this game. Worlds Apart is set in a forest near a beach. The forest part of the game is extremely similar to She's Got A Thing for A Spring, with vivid nature descriptions, a guidebook where you can look up plants and animals, and a specific animal (the pika/pakal) that seems almost directly borrowed, with slightly similar puzzles.
This made me appreciate both games more, as it helped me see some of the creative process. She's got a thing for spring is rare as being a realistic game without horror or magical elements. The closest game to it I've seen is A Change in the Weather, which came out a year or two before it.
There are some negatives; the game makes the unfortunate mistake of combining a large, nonlinear map with independent NPCs and tightly timed puzzles. This is a bad combination, as Jim Aikin learned with his game Last Resort, which also featured a huge map and tightly-timed puzzles. He solved the problem by re-tuning the game so that time changes are triggered by events, resulting in the excellent Lydia's Heart game.
Other games, like old Infocom games, have tightly-timed puzzles, but generally they have small maps that make replay easy, or confine the puzzles to a specific time and place.
So I just used a walkthrough to see the fun. The walkthrough was wrong in several places, so I had to improvise, and that was fun.