I'm not sure I understand your question. You can only file one tax return. If you file a joint return with your spouse in TurboTax, there's no need to file a second tax return in Credit Karma.
If you forgot some info, amend your TurboTax return. Don't file a different return with Credit Karma. The IRS tracks returns by Social Security number, so the IRS will reject a second return filed by the same taxpayer and spouse through Credit Karma.
You can link your TurboTax account to your spouse's Credit Karma account.
Click on this link for help: Linking your TurboTax account to Credit Karma