I doubt very much that the cage aggression has anything to do
with her being an Alexandrine. In fact, they are usually
about as laid back as a Tiel or a Budgie. I would almost
guarantee it has more to do with her previous situation. If
you have contact with the previous owners, you might give
them the 3rd degree on all manner of how she was treated, how
was she about the cage, did anyone torment her, etc. They
may have always tried to "grab" her out of her cage instead
of allowing her to come out on her own, if she wanted to. In
the meantime, I'd just handle her as I would any other
parrot having the same issues. More cage open time, more out
of cage time, as much time with you one on one as possible.
I know you know the drill. Just lots of patience. Good luck
with the little lady.