There are posts for other characters as well. Wynne prefers if you do things like side with the Dalish, Caradin, and obviously the mages. The first is when you first see her. The other place is right after you find Cullen and are about to go up to the Harrowing Chamber.
Wynne is a much-underappreciated character from Dragon Age: Origins. This is because she is easily missed, as your choices can force you to kill her. Her not being romanceable is also part of her being an underdog in terms of popular characters. However, she is a major character in the world of Thedas. She was one of its most powerful mages. She was a well-written mentor as well. She did not cloak herself in mystery in order to seem more wise, like most one-dimensional mentor characters.
Wynne was a mage of the Circle in Ferelden , and one of the possible companions for the Warden in Dragon Age: Origins. Wynne was born around Blessed. The freehold, known as Langwynne, would be her namesake, as she apparently did not have one when the farmer's wife found her in that hayloft. Wynne was a model student and underwent her Harrowing years ahead of her peers, just before she turned seventeen. Within two years she would be given her first apprentice, an elven boy, Aneirin.
They've already addressed this. The novels, comics, movies, and all of that are set in what they view as their own canon. Aside from never touching such characters again, it would be impossible to account for every possibility in the story. DA2 doesn't import any information about what happens to Wynne.