To this date I have never seen a legitimate reason to submit false information to the United States. The honest response is what you just said, that because you are married your parents aren't going to be supporting you financially. Based on what you said, when he applies, having a married sister wont prevent him from going to school.
This question has several answers and you should really speak with an attorney. You have a divorce to consider as well as Immigration issues to flesh out.
I would recommend speaking to a divorce attorney in your area but you can speak with any Immigration attorney in the US.
The short answer is that a green card based on marriage requires a bona fide marriage to be approved. If you withdraw the application, or get divorced, you wont be approved through marriage. Whether you have any...
It should permission in that case, especially since this request is submitted with a different application. However, be sure to submit the prior approval documents and answer the corresponding questions on the form.
You can hire a notario if you want. If you are comfortable with the product and feel free assuming 100 percent responsibility, you wont be the only one.
This procedure could be simple, or a bit tricky. We don't know for sure yet, but we do know that Attorneys can assist you with legal problems by understanding the law and we have a reputation to uphold to consistently get US approvals.
Based on your question, we (Immigration attorneys) would need a touch more info, some documents,...
We don't know the price yet, but we can prepare quite a bit based on our experience with the USCIS. I don't mean just my firm, but many Immigration attorneys. Many will even help you remotely. I don't think it will be expensive for you.
Here's a video with some basic info about the Executive Order.
Most law firms are familiar with USCIS and are anticipating the procedure. My firm is already assisting many clients to prepare their applications and since the task is relatively straight forward, so are the fees. I can't tell you on avvo whether or not you qualify but start with this video and give us a call if you have any more questions.
Looks promising so far but all we have at the moment are general details. This is a good opportunity to ask questions as we wait for more information from USCIS.
Here is a video for you to review, call us with any questions -