How did she 顶替了别人的名字来这里?

Fake passport? She went to the visa interview herself (then what is the point)? If she went to the interview herself and got the visa, why bother 顶替了别人的名字?

Just don't get it. How did she do it?

Moreover, is she still using that other person's name? She got married under that false name also?

What she did is very serious, and I don't think she should come clean now. It will be self-incrimination.