I don't know how this would happen, maybe sangshen and yishan never met, maybe yishan died instead of her, but au where wukong's celestial bride is sangshen.
OOOOOOh this would be so awkward for Wukong who looks at the black fur and six ears on his bride and blue screens. He can’t treat Sangshen cruelly when she looks so much like Macaque. Macaque, in turn, wouldn’t be able to hate his long lost sister as easily, especially with how overjoyed she was at his survival.
I’d say that for this to happen, Sangshen would have to be a widower. Yue would still exist as the clan would need a bargaining chip so Sangshen would be the bride. She would definitely beg for FFM to save her daughter (and Shanzha). Due to the timing, Sangshen wouldn’t have much time alive anyway so would live the rest of her life quietly as Wukong’s wife by name. She would raise Yue and shower Macaque with all the love she missed out on giving until her final breath.
FFM would mourn their second Queen.