Advise needed on entering US with B2 visa

[c-mermaid]

Hi everyone,

I have a mix problem here and if I'm writing in wrong place, please forgive me. Here is what I'm wondering about. I got my green card visa and am planning to go in March with my sister who has recently got a B2 visa. What forms do we need to fill in on the plane? How should we complete the custom declaration form, jointly ( only one custom declaration for two of us) or separately (one for each)? And if we are to complete this form jointly, will it affect her adversely?

 

[cafeconleche]

Just the customs form, though I'm not sure if adult siblings constitute a 'family' in this sense, especially since one is actually immigrating... interesting question.

 

[c-mermaid]

Thank you cafeconleche,
After some thoughts we decided to go by separate flights.