There is a difference between dictating, and pointing out inequality.
As a feminist I try to detect and avoid gender inequality, including when I find myself internalising it. Discussing the ways it crops up with other feminists, or just with people in general, is part of the process of learning to combat it. Sexism and inequality is all around us, and so ingrained that it often goes unnoticed. Talking about it, pointing it out, understanding it is important for those who want to try to change it.
That does not mean in a million years I would ever go up to Amal, or any other woman who has changed her name on marriage (and I know many, many of them including close friends) and "dictate" to them that they shouldn't do it or shouldn't have done it. If they want to discuss it, I'll give my views and explain why but I respect their choice.
As women often contribute to perpetuating equality, it's totally fair to point that out. It is not feminist to want to protect all women from ever hearing that you disagree with anything they do. It is not feminist to tell all women that whatever choice they make is fantastic.
If you want an extreme example, FGM is often promoted and practised by women who strongly feel that it is something that must be done to their daughters/granddaughters to save them from being an outcast/dirty etc. Now, are you saying that you think it's feminist to say "Oh OK then, a woman made that choice, so as a feminist I must applaud it"? Or would it be more feminist to say "hang on... in the interests of equality and women's rights, I'm actually opposed to FGM being enforced on girls".
I think a lot of people are confused about what feminism is, and this "surely feminism is about women having a choice" thing gets bandied around all the time. But if you follow that through to its logical conclusion, no, it's not the case that ant choice a woman makes is fine. If you think about it, there are all sorts of things that we don't have a choice about, male or female. Society restricts choices and rightly so. The question should be, is it fair, is it equal.
For me, it's quite simple - feminism is about equality. Every day when I encounter situations, the acid test is "is it the same for a man? Is a man expected to do what a woman is expected to do in this situation? Are men and women/boys and girls getting the same deal?" And I'm equally bothered if men are getting an unequal deal too, as in not being allowed to have long hair at school for example, because anything that acts against equality is unhelpful.