Just about everything in her books happened somewhere, just not all at the same place and time. Some 80s USA, some communist Romania. Just about everyone has oppressed women at some point or other, and continue to do so.

https://www.penguin.co.uk/articles/2019/09/margaret-atwood-handmaids-tale-testaments-real-life-inspiration

I think the only unrealistic part is that she gets away rather than killed… The TV show especially has her in particularly thick plot armour.