Alternate forms of ID for US passport app
 

My youngest brother's fiancee is from St. Lucia, so that is where the wedding is being planned, with a very short time frame (jeez, maybe she's pregnant?) for this July. My son's girlfriend has an expired US passport from when she was < 16, and she cannot find her birth certificate. (Her parents both recently moved and she is now living on her own). So I know I needed to take her to get a passport in person anyway, and expedite the application, but if she cannot locate the birth certificate, the state dept website indicates "Secondary Evidence of ID" https://travel.state.gov/content/pas...evidence1.html but is sort of vague on the required forms of alternate ID. I can do the Identifying witness part; my son and her have been dating since he was 17, but what hard copies should we take besides SS Card? She does not have a library card, and it just says "example" and lists a few types of id. Should we just load up on anything that has her name printed on it? Anyone ever used this alternate ID to get a passport? Maybe it would be easier (but NOT faster) if she got a new copy of her birth certificate THEN applied for the passport?

what state was she born?

May different from states to states, but you could probably get the birth certificate from either the city she was born, county or the state - call them up and see if anyone of them would overnight it for extra fee.

Probably faster too. Your passport application can be delayed for all different reasons, and lack of primary ID could easily delay your application much longer than the time it takes to get a new copy of the birth certificate.

https://www.visahq.com/us_passport_requirements.php

I don't have time to track this down on the US CBP website, but perhaps this will help.
(bolding mine)

Since she is now an adult, and her previous passport was issued when she was <16, she has to take the oath herself and essentially apply for a new passport using form DS 11 which requires "proof of citizenship". But I'm going to have her track down everything she can with her name on it and take her to the courthouse Monday, and I'll just have her get a copy of her birth certificate. She needs one anyway. She was born in Texas. I'm feeling the cost of our flights increase by the minute. And I suddenly feel like I have a second child.

The only times that we needed to present a birth certificate when applying for my daughter's passport was when she was younger than sixteen. The last time that she applied for a passport, when she was 16, all she needed was her old passport, which was issued when she was 11; no birth certificate was needed.

I have a vague recollection that in order to be used as proof of citizenship, an expired passport must be within five years of its expiration date.

If the last US passport is expired by more than some period of time, then the proof of citizenship and proof of identity becomes an issue during the application process in a way it otherwise wouldn't be.

I have previously ordered multiple certified copies of the birth certificates and have had them distributed for safe-keeping. In part this was done by me due to wanting plenty of proof of citizenship and plenty of proof of identity available in case of adverse events/circumstances.

Some states have made it harder to get certified copies. IIRC, New York has also made it tougher to get such things.

My last passport I had to get with alternate identification because my passport and all of my ID was stolen and I had to make a trip immediately. I had a family member with ID sign a form that said they swear I was really me and basically threw every oficialish document I could find at them that had identifying information. Several very old expired state drivers licenses/ID's, an original Social Security Card, my original High School Diploma, marriage license, divorce decree;), W2's, and some bank and brokerage statements. I immediately ordered a new certified birth certificate but did not have it in time for the passport application so I did not submit a birth certificate. I was in an extreme rush due to an upcoming trip and at the time there was not a passport office accessible to me so I paid an agent to walk it through the passport office. It was not cheap but I had my passport in 4 days.

HOWEVER, The OP is talking about a trip in July. That is plenty of time to obtain the correct documents and that is surly that is much better. Everyone should always have a certified birth certificate in their possession anyway, even if they aren't applying for a passport. You never know when you might need to apply for a job or something. There is info online for getting birth certificates from all the states here http://www.cdc.gov/nchs/w2w/index.htm

Also edited to add. The OP stated the girl was born in Texas. As was I. It's been 9 years since I obtained my Texas birth certificate so maybe things have changed but at that time you could get your Texas birth certificate from either the State, OR, from the County Clerk. I was able to just call the County Clerks Office for the county where I was born on the phone and talk to the actual lady who handles birth certificates. That was WAY more expedient than dealing with Texas state, who simply acts as a middle man and forwards such requests to the County Clerk anyway. It only took a few days for me to get my Texas Birth Certificate, though in my case it was still to late for my passport application.

There are two separate requirements which seem to be getting mixed up. There is proof of citizenship and proof of identity. Birth certificate is only a proof of citizenship. You can't provide secondary means of proving citizenship. But the old expired passport "probably" will work as proof of citizenship as long as it's not damaged.

An expired passport might also work as proof of identity. It's not clear from the rules. If it counts as primary proof of identity, nothing else is needed. Birth certificate is not primary proof of identity by itself (though it may help as secondary ID)

If it were me I would take everything down to the post office and see if she can file a new application easily. It might be a lot simpler than you think. Take her SS card + high school student ID as well.

If not, then they'll tell you whether you need additional proof of citizenship (getting birth certificate) or additional proof of identity. Which may require applying for a state ID, possibly requiring birth certificate as well.