How can my spouse and daughter apply for green card?

As you may know, eligibility for naturalization includes two similar-sounding, but different, components: (1) legal residence and (2) physical presence. In general, a single absence of 180 days will trigger a rebuttable legal presumption that a Permanent Resident has abandoned his/her residence in the U.S., and a single absence of one year or more will trigger a non-rebuttable legal determination of abandonment of status. Beyond this, a petitioner for naturalization generally must show that during the relevant period of time (generally, the 5-year period immediately before the filing of the petition for naturalization, plus the period between filing and date of oath ceremony) he/she spent no less than half of all the days physically present in the U.S. There are some exceptions to these rules, but more information would be needed to assess whether they might apply to your children. Especially in light of the risk of an adverse determination about "abandonment," as well as the importance of success with the naturalization petitions, it would be wise for your family to engage an immigration attorney to carefully review all of the details about each child, to assess eligibility and to properly handle the naturalization petitioning process. Some immigration law firms, including mine, offer legal services on a "flat fee" basis so that a client will know the total expense from the very beginning, and a few immigration law firms, including mine, offer an initial consultation free of charge.