She is on a B2 visitor visa. She has come over after we lived together in New Zealand. We got married in the US. I was recommended this website by a friend who also brought their spouse from another country and went through the immigration process. They said the i-94 would update and she would get a new visa number. If this was confused or not not the case that is fine, I just want to know if she can stay so we don't face any problems. I mainly want to know mailing it off is safe enough, or if I should rely on a receipt notice before she is allowed to continue her stay.
We have only submitted the i-130, i-130a, i-485, and i-864 no additional applications. Thanks everyone for the quick replies. It means a lot!