When you initially posted this message, making inquiries re DP (Displaced People) was more complicated than it is today. A few yrs ago all the documentation for DP was gathered and stored in Bad Arolsen Archives. These are still being digitized, but you can still submit an inquiry.
Luckily Germans kept exc records during WW2. These records are now available to immediate family free of charge. Turn around time can be a few days or as much as six months nowadays. This archives contains the entire history of your Mama, who was an Ostarbeiter/Forced Laborer. There are also personal details like exact place of birth, name of parents, etc. All you need to do is submit full name and exact date of birth. You can e-mail your inquire. Don't forget to include your full address and be patient.
After you access link, click INQUIRIES BY FAMILY MEMBERS.