This part of Armida's made-up story is its weak point: if the city of Maraclea, though ruled by Muslims, welcomed the Crusaders and made some sort of pact with them as other cities did, Godfrey should be able to detect Armida's lies describing non-existent political problems that are supposedly taking place there. Anyway, her sex appeal can easily manage this.
But the most juicy and malicious part in her speech is this reference to her mother; not her true mother (who was a mermaid in Babylon, see previous posts), but her made-up one. So, it is all the more significant that Armida adds a detail just for the sake of doing it: her having died and ascended to heaven. Since Christians at that time - and not only at that time -, as well as Muslims, believed they had a monopoly on salvation, Armida defies them by likening her mother to a Christian saint; as well as her father, as she will say in octave 46, that won't be reported.
By the way, shifting the her real mother: Do mermaids die?
The final verse, putting the death of Armida's mother in parallel with her own birth acquires a thrilling nuance if we recall EA Poe's story Morella.