You can apply under Freedom of Information Act [FOIA] requesting your entire immigration file using the Form G-639. FOIA requests are taking anywhere between 3 - 6 months. Please visit www.uscis.gov for additional details.
By "renovate" do you mean change your non-immigrant status to immigrant status? If so, once your sister becomes a United States citizen, she could petition you as a sibling but the wait is quite long for a visa. Also, once your children are adults, they can also petition you for permanent residency. You may have other options available. Please seek a consultation with an experienced immigration attorney in your area.
You should seek a private and confidential appointment with an attorney. Viable evidence for successful VAWA's include, among other documents: medical records; police reports; and affidavits from family and friends; etc. There are organizations and attorneys who may do your case free of charge. Please contact Legal Services of Southern Nevada and/or Catholic Charities of Southern Nevada and see whether they may be able to assist with your immigration and safety concerns.
I agree with my colleague above. Please present your current custody order to an experienced family law attorney to understand what rights you currently have and what chances you may have for having those rights modified in Court.
More facts are needed to answer your questions. Is your husband a United States citizen? Did you enter the United States with inspection/with a visa or without? If your husband is a United States citizen and you entered WITHOUT inspection or without a visa, you may still be able to obtain your waiver from within the United States. The 601 waiver is now being processed within the USA. You should seek consultation with experienced immigration attorney to explore your options in greater detail.
If you have already received your Receipt Notice from USCIS, the next step would be a request for biometrics by USCIS. The Biometrics Request will indicate the date/time/location for when/where you go to have your fingerprints/biometrics taken by CIS. You may also receive an RFE of Request for Additional Evidence if required documentation mis missing from your file.
You will still remain eligible for a VAWA Petition subject to the other facts of your case. VAWA Eligibility requirements for the spouse of a United States citizen / Permanent Resident may be found at www.uscis.gov
You can make an infopass appointment with your local office at www.uscis.gov The infopass will allow you to appear in person at your local CIS and inquire about the status of your case. Please take with you copies of your relevant documents used for the naturalization petition.