mightily ... strong - not supported by manuscripts. But A, B, Vulgate, Syriac, and Coptic read, “with (literally, ‘in’) a mighty voice.”
is fallen, is fallen - so A, Vulgate, Syriac, and Andreas. But B and Coptic omit the second “is fallen” (Isa 21:9; Jer 51:8). This phrase is here prophetical of her fall, still future, as Rev 18:4 proves.