Can you document the following (as a sponsor)?

As a citizen of the United States, you may sponsor a spousal and his/her dependents (children 21 and under) to become a lawful Permanent resident of the United States of America by obtaining what is often referred to as a “Green Card.” To do so, you need to sponsor your spousal and be able to prove that you have enough income or assets to support your spousal and his/her dependents (children 21 and under) when they come to the US.

If you choose to sponsor your spousal’s Permanent residency /Green card, you must agree to be his or her financial sponsor. If you do not meet the financial qualifications, you will need to find a joint-sponsor to make this commitment.