Do we need H1 document in hand to file H4?

Am getting transferred to a new location from TX to TN and my wife is in India, I have certified LCA for the new location, can i initiate the H4 visa process for my wife? or do i need to wait till i get my H1 Extension approved ?

Note that she had faced H4 visa rejection(Section 214B) earlier due to first cousin relationship. Since first cousin relationship is legal in TN am willing to process for her again.

You can’t file H4 if she is not in US. However she can go to stamping directly using your valid H-1B Approval