1) Does the spouse use the exact same method as the primary? Another word, she report the total and adjust half as she is a nominee.
Yes, but the primary has to issue a 1099 to the spouse.
Please see this answer from @Tom Young and see the link for a thorough discussion.
The IRS has instructions on what to do when you receive a 1099-B as a nominee for someone else:
You put a code of "N" in column (f) of Form 8949 and then
"Report the transaction on Form 8949 as you would if you were the actual owner, but also enter any resulting gain as a negative adjustment (in parentheses) in column (g) or any resulting loss as a positive adjustment in column (g). As a result of this adjustment, the amount in column (h) should be zero."
1099-B
For instructions on how to create a nominee form, please see this answer from our knowledgeable tax expert @DianeW777. Although it is for a 1099-S, the idea is still the same.
Nominee
