If I want to cure Serena for .... SPOILERS...






...





....Vampirism I must:

1: Never talk to her about Molag Bal and how she got uhm... forced lovin.
2: Never ask if she wants to get cured (Her stating it is a gift)
3: Ask if she is allright at the end of the MQ.

That is the only factors right? This is my 3rd character. Ive failed to get the option to cure her the two previous times and Im sick of not getting that option :S

If there is a dialogue option that concerns her condition and well being, then always choose it first.
Remember to tell Valerica that She will not be forgotten, and Serana and your character will return for her when the prophecy has been stopped.
When leaving Ancestor Glade, choose the dialogue to ask Her if her father can be persuaded to change, let Her condemn Him.

This is almost as difficult as getting a Deadra Seducer moved into a Telvannii Tower in the Oblivion Mod Integration-The Stranded Light.

Thanks Brad

Also, who you side with is irellevant right? I assume I can still cure her if I play the vampire side?

Nope, you have to side with the dawnguard. It makes no sense to cure her as a vampire.

I didn't follow a specific formula. I just made sure that my responses to her were always nice or empathetic and at the end of the Dawnguard MQ she just stated that the was going to see Falion or whoever and get cured.

She came back to Fort Dawnguard a few days later and was human again.

Wait...you can cure serana? I did not know that.