I just wondered, is she really a Vampire Lord/Lady? she never transforms.

I am not completely through Dawnguard yet, just came to Soul Cairn.

Just wondering, have anyone ever seen her transform?

She is but will not change into the lord form.

THANK GOD for that. It would totally destroy my hot fantasies about the chick.

Or make them.....................

She is a hot "dead" chick

I just thought she would transform when I do, just when you sneak and your followers sneak.

I tried searching the nexus for a mod that does this but no luck.

It's a shame that she doesn't, I'm guessing there is only one model for a female vampire lord so things would end up looking like you and your evil twin.

Not really, you could give her the cape Harkon has to differentiate or rely the modding community to make decent armour.