US Immigration from Mexico

My daughter has been going to school here in mexico since she was 3. Is it too late for her to start kindergarten in the USA? Is there any official papers we need to bring to the USA to prove she went to school here in Mexico? We are moving to the USA Oct 17th and my daughter is 5.

This will be my wife's (CR1) and daughters (CRBA/passport) first time traveling to the USA. When we reach the POE(Houston) is it ok if I join them in the "immigrant" customs line even though I am a USA resident?

There is still not activity(almost 11 months) by USCIS on our CR1 I-130 application. The processing times have become so long I am sure others will encounter this problem. I had to renew my passport recently and now it has a new passport number. My wife will also need to do the same with her passport. What is the process to notify the Service center to update the change in these documents? I am US citizen and wife is Mexican citizen.

https://www.cbsnews.com/amp/news/public-charge-rule-judge-blocks-attempt-to-deny-green-cards-and-visas-to-low-income-immigrants/

USCIS posted a new I-864 Form that must be used starting on 10/15/2019. However, I looked at the new and current forms (side by side) and can't find any differences.

Does anyone know what changed, besides the edition number?

https://www.uscis.gov/i-864