I think there is a very strong chance she survives and we will see her again next game, hopefully as a companion. The ex-slave heart of steel but treats her servants well, even non mages, and wants to see them raised to full citizenship of the Imperium, would be a nice counterpoint to our current noble warm hearted Tevinter mage who sees slavery as an alternative to poverty.
If she jumps to her death, you don't see her land. She leaps into a waterfall so could definitely have survived.
If you let her go, you never see the confrontation with Corypheus. May be it never happened because she had second thoughts about it; may be she was flattened but not killed outright and recovered; may be even Cory had a soft spot for her and so spared her in spite of her "failure" over the Well.
WoT2 definitely leaves it ambiguous and thus perfectly possible for her to return without it contradicting anyone's choices in the game. Even her name could change, since it is clear it is one that she took for herself rather than her birth name, so it would not be apparent immediately that it was her if they chose to make it that way (face damaged and restored or wearing a mask) and introduced by a totally different name.