Thompson's Oz work was not limited to her novels. She also wrote a play, songs, and several poems about Oz, as well as a partial story for a contest called "The Enchanted Tree of Oz." I have yet to read Thompson's play A Day in Oz, which the International Wizard of Oz Club reprinted in Sissajig and Other Surprises, but they did include "The Enchanted Tree" and a couple Oz poems in The Wizard of Way-Up and Other Wonders, which I do own.
More importantly, in 1992, the Club issued a 32 page booklet of a selection of Thompson's Oz poetry entitled The Cheerful Citizens of Oz, illustrated by the late Rob Roy MacVeigh.
Thompson's Oz poems are definitely cheerful and jolly, sometimes describing a character, and sometimes telling a story. Quite a bit of fun to read, and my only dislike of Cheerful Citizens was that it was so short, it was easily finished in a half hour.
I can't say much about "The Enchanted Tree of Oz," because while it did have an interesting premise, it doesn't have an ending. The contest was to finish the story. In it, the Scarecrow, Dorothy, the Tin Woodman, and the Lion find a tree and the Lion and Dorothy disappear once they attempt to climb it. What happened next was for the contest entrants to decide. The contest was revived years ago by the Oz Club when they reprinted it in the Baum Bugle.
Thompson made Oz her own in her books and other writings, deftly taking over from Baum. She made some odd story choices and even got quite wacky in some of her descriptions of events, leaning more to nonsense than Baum ever did. Her earlier work suffered at times of this. But as she began to create her own leads, she became more confident in her writing and her work improved vastly. Her contribution to Oz might not be universally loved, but it definitely cannot be ignored.
But speaking of that, who took over the Oz series after Thompson left Reilly & Lee?