Chances that she is a npc in the next game regardless of when/where it takes place? I know some do not like her just looking for odds. If she is does that increase the chances we see vampire lords?

not likely. putting the cure/non-cure issue aside, TES isn't known for recurring characters.. there are only a handful throughout the entire franchise other then Daedric Princes.

Not likely. There are only two NPCs from previous games that I can recall off the top of my head who have made an appearance in a later TES game, and they were both in Morrowind. The first is St. Juib (he talked to you at the very start of Morrowind while you were on the boat, and then appears in Skyrim as a ghost in the Soul Cairn). The second one is Neloth, who appears in Skyrim (on Solstheim) if you purchase the Dragonborn DLC. There may be a couple of others, but they're very few and far between. The fact that she's added by a DLC makes it much less likely; Neloth and Juib were in the base Morrowind game.

The most you might get is some passing reference to her in a book or some conversation with an NPC.

Well she is immortal and they seemed to invest a lot into her? Plus she survives both choices

She was also locked away in a cave since before the empire existed. Remember she has no knowledge of it and is surprised to find out Cyrodiil is the heart of it. So if she were included the game would have to take place either pre-empire or post-skyrim.

You forgot about M'aiq the Liar, and Sinderion.

although you just find Sinderions Skeleton, it's still a re-appearance.

I knew there were others - they just hadn't penetrated the cobwebs in my skull.

Count Janus Hassildor was also Immortal, but we have never seen him since... wish we did though...

and She can get cured if you side with Dawnguard.

And they didn't invest much more into her then any other central character of a given plot line...