My sister’s abusive husband does not want to file papers so she can become a permanent resident. What can I do to help her since

If your sister's husband battered your sister or her daughter or subjected either of them to "extreme cruelty," your sister may be able to self-petition under the Violence Against Women Act. You would want to get help from a lawyer on presenting evidence to show this. If she cannot afford a lawyer, there are many pro bono clinics that offer help with such petitions. www.ImmigrationHelpAttorney.com

I agree with the other attorney. (1) have her move to a safe place; (2) meet with a lawyer to discuss VAWA options.

I agree with my colleagues.

She appears eligible for the I-360 Self-Petition as a battered spouse. She will need to prove that the marriage was bonafide (which is easy so long as her husband is listed as her child's father) and that she is the victim of domestic violence (which you can show with police reports, medical records, photos, declarations, etc). Because she has overstayed her visa, she now has unlawful presence which will prevent her from adjusting her status based on a sibling family petition (not to mention that it will be a 10 yr wait). The unlawful presence will not be a problem in a VAWA (I360) Petition or in a USC spousal petition.