Raven

From TLJwiki

A name given to April Ryan by the Rebels. This might come from her dark hair and clothes, her previous association with Crow, and her new persona as a warrior and leader within the Rebels. The name appears to have been bestowed on April out of affection and respect, but it also serves as a useful codename to conceal her identity.

In Norse mythology, Odin - the god of wisdom and warfare - was attended by two ravens, Huginn and Muninn (Thought and Memory) who flew across the world and reported back to Odin every night. The raven is also associated with the clever trickster god, and is often featured in Native American creation myths. These traditions make 'Raven' a good name for April.