Hello and thank you for your help. My sister is having her F4 IV interview in a few days and today, the embassy sent us a list of documents to be either submitted to the CEAC or brought to the interview.   
    I have pasted the part where I have some doubts and to give you some background, all the required documents were uploaded and approved by NVC in November 2019, then  everything came  to a halt.   
      Based on the embassy's email below, here are my  questions and concerns: 
    1. Do I keep the forms I-864 & I-864A as is,  do I start from scratch? or do I add new ones? (it says: "most recent federal IRS tax Transcript). The forms uploaded have our 2018 tax information and the 2 years prior to that.   
    2. Do I upload new IRS transcripts in addition to the ones uploaded? (similar question) 
    3. We  made about  75K because I was unemployed most of 2021, 30% less than the previous year.   
    4. Do I  need to get  health insurance for my sister? (unrelated question) 
       
    Below is a portion of the email. Thank you so much for the help. 
       
    "The following documents  must be uploaded to the CEAC  at  https://nvc.state.gov/ceac:     
       
    o                Financial documents from the Petitioner, including: Form I-864     Affidavit of Support, most recent federal  IRS Tax Transcript, W-2s, and if applicable, Form I-864A     Contract between Sponsor and Household Member.   
    o                If the Petitioner does not meet the financial guidelines, the Petitioner must find a Joint Sponsor, and upload the financial documents including: Form I-864     Affidavit of Support, most recent federal  IRS Tax Transcript, W-2s, and if applicable, Form I-864A     Contract between Sponsor and Household Member.   The Joint Sponsor must also provide proof of legal status as a U.S. citizen or Lawful Permanent Resident.