Do I need to fill out two separate I130 forms for my wife and stepchild who are already in the US or do I submit one I130 form? My stepchild is 17

To request an immediate relative, for example, an spouse. A petitioner must complete forms I-130 and I-131. In the I-130 the petitioner is asked different questions, among others for whom he is petitioning. If the beneficiary's children live with the beneficiary spouse and will immigrate with her, the petitioner spouse must include the children too. No separate form is necessary for children beneficiaries. Now, as to any additional issues to consider or the documentation that must accompany the petition it is best to consult an attorney.