Form I-751 filing method depends on marital status.

[nancymervin]

When it comes time to renew your conditional green card and remove conditions on residence, who files will depend on your marital status. If you are still married to the person who helped you secure your green card status, both you and your spouse will file Form I-751 together.

If you have children who are dependents who received their conditional green card when you did and entered the US within 90 days of you on a K-2 visa, you can also include them on Part 5 of your Form I-751 application. If your children arrived more than 90 days after you or entered the US on a different visa, they will need to file Form I-751 themselves to remove conditions on residency.