Yes. Your stepmother can petition for her mother even if she is not working. However, someone (family relative, friend, etc.) will have to agree to sign and file an affidavit of support for your stepmother and her mother. This can be you, your half-sister or anyone else. If they meet the financial requirements for the affidavit of support there should be no problem. I strongly suggest that you contact an experienced immigration law attorney for a face-to-face consultation and give him/her all of the facts surrounding your stepmother's case. He/she would then be in a better position to analyze the case and advise you of your options. The attorney will also be able to provide you with guidance so as to streamline the procedures and assist you in making sure everything goes smoothly.
Answered on Jun 22nd, 2012 at 4:36 PM