I heard Damu Anna didn't have any children. Did Sai Baba help him with that?

Yes, the sacred text addresses this. Chapter 25 mentions that the devotee Damu Anna had two wives but was without children for some time. It explicitly states that by receiving Sai Baba's blessings, he was subsequently blessed with sons. This event is presented as an example of Sai's nature, as the text notes that once one-pointed faith is established in a devotee, Sai wards off their misfortunes, removes their suffering, and grants their desired objects. Damu Anna's story serves as a testament to Sai's readiness to protect and provide for His devotees.