Welcome back to the Wefugees Community and thank you for reaching out to us again.
I assume that your girlfriend applied for asylum when she came to Germany and the BAMF decided on a deportation ban for her. This means, that she did not receive an asylum status, a refugee recognition or the subsidiary protection, but another humanitarian status.The BAMF most probably saw her facing potential threats regarding her and the (unborn) baby's health/well-being in case she would return to her country of origin. The immigration office subsequently issued a residence permit according to section 25 (3) of the German Residence Act. As the baby was born in Germany and its mother holds a valid residence permit, it received a residence permit according to section 33.
Regarding the passport: For now there is nothing like an EU passport. Your girlfriend would need to apply for German citizenship to receive a German passport. Please follow the link for more information on this. Regarding your questions on the Nigerian passport, I would highly recommend to discuss this topic with a lawyer. As you apparently face difficulties in the communication with your lawyer, it could be helpful to contact a counselling office. I am sure they are happy to support you in addressing and formulating all the questions to your lawyer and explaining more complex circumstances also in a patient and understandable way.
All the best,
P.S.: I saw that you opened another thread with roughly the same content. In order to keep a better overview and information in one place, I will close that one. I hope this is okay for you.