It's just "expected" that a wife changes her name to that of her husband, maybe there's still peer pressure from family or hubby to do it and the wife simply doesn't want to say no and doesn't want to cause a rift with the in-laws!
My in-laws don't have free license to dictate to me what my own name is or refuse to address me by it, but unfortunately this is precisely what's happened.
MiL has been asked to stop this numerous times by DH. She hasn't. On one occasion she did address something to me by my correct name but made a point of misspelling it (at that time she was on my Facebook so she could clearly see both my name and its spelling). The next time she reverted to Mrs Hisname.
This has led DH to conclude that either she's not very bright or she's trying to make a cheap point. Refusal to acknowledge someone's own name is about as disrespectful and rude as it gets. She's divorced from FiL but I have resisted the temptation to address her by his (and DH's) name - even though she has more of a claim to it than I ever have. She's used it - I haven't.
We married in 2008. It's been a constant well of surprises to have received so much rudeness and pushback (often in casual transactions) for something I'd expected would be pretty commonplace by that time. This was usually in situations where my marital status was listed as married but I didn't use the title 'Mrs'.
I made the mistake of assuming that by the 21st century no one would give a stuff what women call themselves. The passive aggressive or outright rude conservatism I've experienced has been quite the eye-opener. In some ways, I believe attitudes to women have regressed rather than progressed in the last 20 years.