She is 7 years old and US citizen, can she go back to California with her uncle without a letter of consent ?

No, not a good idea. Not because of immigration but because of potential issues of child abduction.

Waiting for a decision by mail.

You should go to the Asylum Office in person and ask about your case. The Asylum Office has walk-in hours on Fridays from 8:00 a.m. to 12:00 p.m. ...

How to pay fee's for affidavit of support ?

I am surprised that the embassy has scheduled the interview without you paying the fees and filing the affidavit of support. Did you pay the fees...

Its that means i have to have an interview then i can get green card? why next step and the main information shows different?

The USCIS case status interface is not very clear. It is also often inaccurate. In your case though, it appears that you will be scheduled for an...

Do I need to fill form I - 864?

You will need to file an affidavit of support, but you should check to see whether you may be eligible to file Form I-864 EZ. As the letters...

Yes, you can. You only need to show your valid ID and boarding pass to board a plane. Nevertheless, it doesn't mean that it is a good idea.

If you have an interview "very soon," you may not receive the FOIA in time. It takes several months to receive one. Nevertheless, you should try....