The I-94 is proof of lawful status so as long as it is valid she is OK. You should file an extension at least four months prior to its expiration and the USCIS will issue a new I-94. Only if she travels outside of the US will she need a new visa stamp to reenter.
1. Not necessary.
2. No. She needs to take a copy of your H1B approval notice, marriage certificate, and your pay stubs with her.
This answer is of a general nature and should not be relied upon as final, nor is it intended as legal advice. Consult with a qualified attorney before making any legal decisions. Gen Kimura, (832) 247-6932.
I agree with Atty Morales.
(213) 394-4554 x0 Mr. Shusterman is a former INS Trial Attorney (1976-82) with over 35 years of immigration experience. His response to your question is general in nature, as not all the facts are known to him. You should retain an attorney experienced in immigration law to review all the facts in your case in order to receive advice specific to your case. Mr. Shusterman's statement above does not create an attorney/client relationship.
My colleagues' answers are correct. The H-4 is not tied to a particular employer, like the H-1B, rather, it is tied to the H-1B visa holder. When she goes to India and applies for the H-4, she should receive it since you are on a valid H-1B with the employer who petitioned for you and she should receive an H-4 visa that runs parallel to your H-1B.
Michael H. Sharon has been practicing immigration law for more than 25 years. His response to your question is not legal advice but only legal information and is general in nature since not all the facts of the case are known to him. We recommend that you contact an experienced immigration attorney to review all of the facts in your case in order that he/she can provide you with advice specific to your case. The statement above does not create an attorney/client relationship. If you wish to contact Mr. Sharon, please send him an e-mail at email@example.com.