No, it is your asumption. and you have this asumption because you assume that girls and women that ask for human rights do it because of western feminism, not because they live in their culture and don't like that.
Again, just read what those girls and women have to say about their forced marriages. Sure, sometimes it is the mothers who sell their daughters. But other times, the girls who were sold grow up to fight against that.
You are passing judgement on the women of those cultures that want change instead of just submiting. But it is their culture too, while it is not yours. Her voices are valid.
Read about what the girls in Oaxaca have to say about their marriages. The rapes and the beatings they receive while being told that they owe submisiveness because they are being "protected" by the man who does the beatings and the rapes. Unsurprisingly, they reject that when they have the chance. It has nothing to do with my culture, it has everything to do with being in their skin. Western men who want to defend sexist traditions like to say that women at other cultures are happy with the sexism because it suits them. And they try to silence the indigenous feminist because if people start to hear them, many of their claims are shown as lies. I've give you a couple of links, you haven't provide any link with women defending those traditions. Or saying "when my parents sold me to an older men as a wife, I was so happy". Go ahead, add the links.
It is not me who is saying that forced children marriage is wrong. It is the gilrs and the women who have experienced that.