O fficial

Official descriptions of Lady from Capcom's sites.

Devil May Cry 3 Instruction Manual

Demon Hunter Lady is as fierce as they come! She despises demons and her life's work is to destroy them all. That goes for Dante as well, with half-demon half-human blood coursing through his veins! Lady has some sort of connection with Arkham, and has followed him to the tower.

Devil May Cry 4

Making her living as a Devil Hunter, her precious encounters with Dante are long and twisted; however, the two have arrived upon a mutual friendship. When she has difficult jobs that she cannot deal with, she gives them to Dante and demands a huge commission later.

Manga

A demon slayer. Her mission statement is to destroy all demons - even half-breeds like Dante.

Anime

Dante's friend and a human devil hunter. She is unruly and will bring jobs out of the blue to Devil May Cry asking him to take them. Dante owes her a significant amount of money, and Lady is constantly redminding him of it.