Whats worse my aunt changed my cousins name to her maiden name when she left her husband, 'as she's a girl' her son wouldn't traditionally have her name anyway.
Am I reading this right, your cousin initially had her fathers surname (let say smith) but after divorce her mother changed her name to her own maiden name (jones) assuming that if she had a baby it would never have been smith, or even jones because her baby would have her Daughters partners name?
Your cousin is contradicting herself, if it's such thendine thing that children have their Dads surname, then by her own logic, she should be smith, and her son should be passing her own fathers name down, she he's #whatevernumberbabysmith.
She had her Mothers name and has also given her child its Mothers name and its is his name to pass down, but your Daughter, who also has the same surname as her son doesn't count because she can't pass it on, even though the very reason she has that name to give to her son is because her Mother did she's assuming your dd can't do? So if she feels your dd isn't the same, or it's different, did she also have the same feelings about herself? That she was different to her make cousins who'd been named after the men in the family?
Makes no sense for her to feel that way as surely everything she feels about your dd applies to herself?
I wouldn't air it on Facebook but I genuinely would correct her privately, every time she says you dd having the surname first is different because she's a girl, is she planning on telling her son this as he grows? What if she or he says it to dd?
I'd be ready to counteract other sexist stereotypes they may reinforce around dd. Like dolls are for girls, trains are for boys or whatever, you may not want to challenge them directly but I would be making sure dd knows It's all a load of sexist bullshit.
There's also a lot of assumptions placed on what the children and society will be like as adults. More and more women keep their own name, children's surnames are often double barrelled, by the time her son is an adult it may be common for men to take the woman's name.
He may not even marry and/or have children. He may be gay. He may identify as female himself as he grows up. There's so many different paths.
I know some people, will say it's no big deal, that people challenging it are hysterical, overthinking, man hating or whatever, but I do feel the small things like passing in the assumption the woman will her name before a child is even born, leads up to the bigger assumptions like stem is a boys thing, and it can impact on their adult lives.
A surname belongs to the person it was given to and as an adult, is theirs to with what they wish, be that change it altogether, merge it with another, give it to someone else, male or female, regardless of birth order.