Maggie (played by Essie Davis) is a crew member on the Mjolnir (nicknamed Hammer). She appears to be the ship's medical officer. She first appears at the end of Reloaded, tending to the unconscious Neo and Bane. While attempting to inject Bane/Smith with something to "help him remember" (possibly sodium pentothal), Bane stabs her with a scalpel, killing her, and then escapes to the Logos.
Her character is not explained or expounded upon at all, appearing only briefly at the end of Reloaded and the beginning of Revolutions. Given her name, she may be one of the few rebels other than Lock to have a real name as opposed to an alias or handle.
Read more about this topic: List Of Minor Characters In The Matrix Series