Chromis

Okay, thank you for your answers. So if I understand you guys correctly, then as of right now, and as of moment of filing the petition, they do not need to be married. But 14 years later, when my brother is joyfully accepted into the US, as long as he is married by then, he will be okay? 

Before this tax bill passes and possibly closes the window of sibling based immigration, I would like to file to bring my brother to the US. I am from Western Europe, and he is as well. However, I have never done this before and I have a question.

He wants to bring his girlfriend / fiancee to the US as well. I know the process would take 14 years for approval. I want to know if on this petition, it would automatically include his fiancee.  Do we have to file separately for her?

What about any children they might have in this 14 year time span?

We do want him and the girlfriend to live in the US. Should they quickly get married so that they can file on one petition, or is there no such thing? 

Thank you for any answers offered.