It is usually better for tax purposes to file married filing jointly.
https://ttlc.intuit.com/turbotax-support/en-us/help-article/taxation/better-married-couple-file-join...
You can change the spouse on the personal info tab in TurboTax, just overwrite the information
https://ttlc.intuit.com/community/taxes/discussion/how-to-switch-taxpayer-to-spouse-line-on-1040a/00...
