@Taran s did she file form I-131 for you before you filed for vawa? If so, you can use the 797 notice of receipt on that form as proof of citizenship. USCIS understands that victims of abuse may not be able to get their abuser's information so they have some discretion with that. You can also have someone who knows she is a citizen attest to it. Don't worry about that so much. I requested a FOIA and luckily got my ex's picture so that's also something you can try.

@Kerry S no she did not filed for 131.

@Kerry S it’s i130 not i131. i131 is travel document

@Taran s If you are still married you can request a copy of her birth certificate using your marriage certificate just request a copy of her birth certificates from the state or if you know the county she was birth in very easy you can do it online. You have the legal right to request a copy of it as a spouse. I hope this helps.

@VAWA FEB2022 actually we divorced now and she born in US

Like as @Kerry S said, if she filed I130 for you then you don’t have to worry. I did not have my ex spouse passport or birth certificate but he had filed i130 for me in the past. my vawa was approved

@mm AA thanks for the correction. @Taran s this is the US, where they have access to everything. Something as simple as not having a copy of your ex's passport to verify citizenship is not a big deal. You know her real name and this is the agency that deals with citizenship. That's an easy pull. If you ever filed taxes together, that's something else you can use, but like @Soon to be Approved said, if you can't acquire any document, just explain that you were not able to obtain that. You're good!