One of the most touching books I've come across with a lesbian stepmother dynamic is 'The Seven Husbands of Evelyn Hugo' by Taylor Jenkins Reid. While not the central theme, the nuanced portrayal of a bisexual woman navigating love, fame, and family—including her role as a stepmother—is heart-wrenchingly real. The way Reid writes about silent sacrifices and unspoken bonds between women feels like peeling an onion; every layer reveals something more tender.
Another gem is 'Written in the Stars' by Alexandria Bellefleur, where the protagonist’s complicated relationship with her stepmother adds depth to the rom-com plot. It’s refreshing to see a queer stepmother who isn’t vilified or reduced to a stereotype. Instead, she’s flawed yet loving, mirroring real-life blended families. These stories stick with me because they normalize queer parenthood without making it the sole conflict.