Interestingly, she agreed with you about how she did a meh job of writing for adults with that book. "Two Kinds of Writing?" The Medusa: The Journal of the PJF 1 (1990): 1-4 The piece is oddly judgemental and has a lot of that nonsense essentialism about how kids are better readers than adults, but it fundamentally gets into how publisher assumptions about genre lead to different writing styles and she found it very difficult to write well to adult fantasy genre conventions.

(and yeah, the sexuality issues in that book are definitely a thing.)