US Immigration from Madagascar

What kind of child custody papers do I need for the green card interview as the husband of an immigrating spouse? My ex-wife and I never filed any formal custody papers. We had one son and he is staying with his mother. My ex-wife has custody but we agreed our son could stay wherever he wanted. He will be eighteen next February and will be graduating from university next June. There is a child support agreement in the divorce papers. I pay her $400 per month.

My fiance arrived in the United States on a K1 visa in mid-December. We married and she applied for permanent residence and work authorization. At the beginning of February, we went to the Social Security office to get her a card. They said she would receive a Social Security Card in the mail within the next four weeks. After not receiving it, we returned to the social security office at the beginning of March. The Social Security office said they had made an error in our address. The card had been returned to their office and they would resend it. They did give my wife the SSN issued to her.

We did not receive a card. We received a letter. The letter says:

"We cannot issue you a Social Security Card at this time because:

YOUR I-94 HAS AN EXPIRATION DATE WITHIN 14 DAYS OF PROCESSING. PLEASE

PROVIDE AN UPDATED I-94 WITH YOUR PASSPORT."

She already has a Social Security Card issued to her, but it was lost in the mail to an SSA error. Getting an updated I-94 would require her to leave the country and come back? Any other way to get her card resent?

Earlier this month,

1) My fiance came over on a K1 visa with her 9-year-old son.

2) I was laid off from my job as an IT analyst.

3) My fiance and I married.

I have my own 16-year-old son.

I have no current income, so I lack the necessary income to support a family of four. My savings and assets are less than required as well. I require a joint sponsor.

A retired family member who rents out rooms for extra income agreed to joint sponsor me on the i-864 documents. Through a combination of retirement plans, social security, and room rental, she should be able to joint sponsor my wife and her son based on income. Although she would be able joint sponsor me based on assets, the documentation to prove such assets would be extremely difficult.

I am thinking she would be required to show enough income to support three (herself, my wife, my wife's son)--$26,662. She would not have to show enough income to support me and me son as well. Is my thinking correct?

Question 2: Any caveats about how she should best support her income?

What happens if the sponsor gets laid off right before filing the i864? The sponsor currently has little savings, no property, and is receiving only unemployment (current income is below the poverty line). However, the sponsor has an excellent income history and a lot of available credit. Can the beneficiary be forced to return because the sponsor is laid off?

My stepson and fiancee had physical exams (a couple months ago) for the fiance visa before they left their home country. They were tested for various conditions and received any inoculations that were missing. My fiancee brought the medical exam in a sealed envelope and gave it to customs on her arrival.

We went to register her son for school today. The school requires the same tests and inoculations to be done before her son can go to school. Is it possible to get the results and inoculation records from the visa medical exam for her son? If so, how? Or does her son need to get examined and inoculated again?