Welcome back to the Wefugees Community and thank you for your question.
Yes, in my opinion, an experienced lawyer can support you with convincing the immigration office (Ausländerbehörde) that going back to your country of origin in order to apply for a visa is unreasonable for you. Especially since you are taking care of your child. We discussed very similar situations here and also here (in German) before. As my colleague explained, the final decision will be at the discretion of the immigration office. I remember from one of your last posts that you hired already a lawyer, right? Did you talk about this issue with him/her?
Good luck and please don't hesitate to give us an update or get back to us with any further questions.
All the best,