She was always a background character, but an important one here because Ghosts naturally flock to those who can "speak" to the Traveler through dreams. Even as a child on Europa where we discover her journal, she had this gift mentioned in her dreams. While this is our first time formally meeting her, we were canonically aware of her presence. I don't think its claimed that she has been with us the whole time but its more that she is "running tactical" for us. She does sigh a lot on the mic though, or maybe it is a "breathy voice?"