Hello Tato. My apologies that the other expert responded before you were able to reply to my request for information. Take a look at this link:
You will see some categories there under the first column (Peru would be in the first column). Your mother, as the parent of a U.S. Citizen that is over 21 does not fit into those categories. She gets a visa immediately and can immigrate to the U.S. within 6 to 9 months or so which is the processing time. She is not waiting for a visa to be available, she is just waiting the processing time. Your brother, unfortunately, is in category F4, sibling of U.S. Citizen and it doesn't matter that he is a minor. The date there is 15SEP03. This means that I-130s filed on or before September 15, 2003 can now be used to immigrate to the U.S. So if you filed an I-130 for your brother let's say September 1, 2016, his Priority Date would be 01SEP16 which means he would have about a 13 year wait for 2003 to get to 2016. This is a waiting line of people that applied before you and nothing in the law allows for anyone to jump ahead of anyone else in line, not even in an emergency.
However, there is a common way around this, though it is not a convenient way. What you do is that you file for your mother as normal. She comes by herself to get her green card when it is time. As soon as she gets her green card in the U.S., she files an I-130 for your brother. Then he would be in category F2A, minor unmarried son of a U.S. Lawful Permanent Resident. The date there is 15NOV14. So he would probably have about a year and a half to two years to wait for a green card. He would come faster through your mother. And yes, I know that you don't want him separated from your mother. Perhaps there is no one to care for him or your mother just doesn't want to be separated. That's fine. There is a solution for that too. She can apply for a Re-Entry Permit on form I-131. This will allow her to be outside of the U.S. for up to 2 years. She can use it for multiple trips. If she needs more time, she comes back before the 2 years ends and then she can apply for one more Re-Entry Permit for 2 more years. If she still needs more time, she can apply again, but after 4 years, they get harder and harder to get and often only grant them for one year at a time. At some point she will need to start living in the U.S. and spending more than 180 days per 12 months inside. Here is a link to the I-131:
The point is that she would probably be in the U.S. just a few weeks or a month or two and could then go back and live with your brother until his turn comes through her petition. Then they can immigrate together. Yes, it means that your mother won't be living in the U.S. as soon as you may have hoped, but as I said, it isn't a convenient solution, but it is the solution we currently have under the law. Luckily he isn't close to turning 21 or then it would be a real big problem.
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