if you read the instructions for form I-912 you will see that the form may not be used in conjunction with an application or petition that requires a person financially qualify - have a sponsor with an income of 125% over the poverty line.
The instructions also provide you with the mailing address.
your best be will be to wait to start on the kids after you getyour green card. however you send the 912 with the I130 only.
The advice that I give in each answer or legal is not intended to take the place of an in person consultation. A complete answer takes an in depth interview. After all, it is a life that is at stake. If you are in another city that I do not service ask me and I might be able to recommend you an attorney there. In general, in Houston, I recommend Adan Vega or Bruce Coane, Specialists. In Dallas I recommend Richard Fernandez or Yong Wood highly skilled and experienced.