My Mom (German) but SSC holder is looking to immigrate. Advice please & TY!

[Melissa Barter]

My mom is a German citizen and lived in the U.S. with my Dad (military) about 20 years ago. They have since been divorced, and she relocated back to Germany in the 90ies. During her time in the U.S., she worked and obtained a social security card, which she still has. It does not have any restrictions listed on it, as far as "only valid for work" etc. leading me to believe she was considered a permanent resident, able to work in the U.S. because she was married to my dad who was in the army.

My Question is: does it mean she is already a permanent resident in the system? Or would she have to start a complete new immigration process if trying to move to the U.S. permanently? Also, she has two minors (my maternal half siblings) that are also German citizens 8 & 10 years old) joining her.

I know I can petition for a family based immigration I believe, with the Form- I130, but wanted to know if her having a ssc would give us a headstart? Also, would I have to fill in a separate form & pay the fee 3 times (Mom, Bro & Sis)?

If anyone can share how and where to even begin, I would sincerely appreciate it. Thank you in advance!

[Melissa Barter]

Ssn

After calling SS, we found out her number is still active. Does anyone know who I can contact to see if she still has permanent resident rights or what we'd have to do to get them?

Thanks!