I'm not an avid fan, but I've read enough about the show - I tend to live things vicariously rather than experience them directly. I don't know whether or not Susan is actually a Time Lord, and it would also depend on whether one accepts the awful America-friendly line in the Paul McGann movie about the Doctor being half-human (ouch). As for Leela, she's human, but (in a story I haven't seen) she leaves the Doctor to stay on Gallifrey with her newly-acquired Time Lord boyfriend. Given that she's human, however, she's probably dead by Eccleston's time anyway.

Ack - it is unwise to attempt serious analysis of a series that was written on an ad hoc basis!