Dear Salome Mkota,
Welcome back to the Wefugees Community and thank you for reaching out to us again.
I agree with Gentle james: while holding a Duldung, it will not be possible to receive Kindergeld. If the other parent of the child holds a residence permit, he/she may apply for the Kindergeld instead. Nevertheless, be aware that the Kindergeld gets largely deducted from other social benefits as well. The respective authorities need to be informed and social benefits will be re-calculated.
I hope this helps and please don't hesitate to get back to us with any further questions.
All the best,