I've only just joined this year's challenge, and have already completed half of it. The two "tightest" fits for me are February (shortest book in my TBR is a regency romance by an author I love, multiple hits) and March (already completed)
The Mirror of My Heart: A Thousand Years of Persian Poetry By Women - so both by AND about women.
My most 'creative' challenge entry is
Indo-European Language and Culture: An Introduction my first and so far only 5-star read of 2026. It has 19 chapters each for a different language
family, making it all about families, and an easy choice for November.