August became her husband because his sister Amelia was the second wife of Pedro I of Brazil (IV of Portugal). And Pedro only married her because once the way he treated his first wife (Leopoldina of Habsburg) became known in Europe no one from the most important royal families accepted to marry their princesses to him. They could only find the Leuchtenbergs, and at first Pedro didn't like the idea of marrying someone from a family that until then wasn't considered noble. He only changed his idea when he saw how beautiful Amelia was.![]()
Maybe those Leuchtenbergs will be a bit more lucky then, in absence of the Coburgs.