Warning: Contains SPOILERS for Creed 3Following the death of one significant character in Creed 3, Creed 4 must resolve the mystery behind another character's identity. Dropping subtle hints surrounding Adonis' past, the Creed series initially revealed that Mary Anne Creed was not Donnie's biological mother. After Apollo Creed's death, Mary only adopted Donnie after learning that the young boy was an orphan. Since she raised him as her own son, Adonis, too, accepted her as his real mother, as seen in all three Creed movies.

https://screenrant.com/creed-3-mary-anne-death-adonis-mom-mystery-solve/