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@pixie374 As I mentioned in my explanation, my girlfriend is both used to it and "not uncomfortable" with the concept of her mother seeing her naked. Nonetheless, it is more that she doesn't mind if her mom sees her naked rather than her wanting her mom to see her naked. She still feels vulnerable when she is naked, and she does not particularly enjoy being naked in front of her mother either.
As for what caused this, I did not make any comments or suggestions that may have done so. She has noticed from spending time with some of her friends that most people do not have the same experience as her, and she asked me what I thought about it. If you want my opinion on the matter, though, I will share it: I do not care if her mother sees her naked at an appropriate time since my girlfriend doesn't mind, but I don't particularly like the idea of her mother actively trying to see her naked every day, and my girlfriend has expressed that her mother's actions make her uncomfortable.