'Deadpool' is an interesting comic creation. There are those who feel that he doesn't truly belong to the superhero genre at all - he's a parody character; one who exists mostly to mock the conventions of regular superheroes. Everything about the character of Deadpool and the world he lives in is presented with a nod and a wink to the audience, and that includes his female alternative.
In the spirit of being on-the-nose, the creators of Deadpool decided that if there was going to be a version of Deadpool who was a lady, you might as well name her 'Lady Deadpool.' They didn't even try too hard with differentiating the names of the people in the costumes either; whereas Deadpool is Wade Wilson, you should properly address this lady as Wanda Wilson. To all intents and purposes, the characters are identical right down to the costume, other than the ponytail which looks as impractical here as it did on Spider Lady.