She lives in a house on the edge of the Denerim Market District in front of the marketplace. When the Warden decides to help Alistair find his sister during the quest Alistair's Family the house will appear when the Warden next enters the market area. (Alistair must be in the party for the house door to be interactive.)
She is not at all happy to see her brother and the only thing that she wants from him is money. When engaged in conversation by Alistair, Goldanna will berate him. The Warden can choose to try to reason with Goldanna, defend Alistair against her diatribe, or urge Alistair to leave, with or without offering Goldanna a gift of money.
Note: The party can offer up to 1500 as appeasement to Goldanna, but she will still not accept Alistair under any circumstances. If the Warden has Master Coercion, using Persuade during the conversation will allow the same result without having to offer Goldanna any money.
When Alistair is drawn into the Fade he is trapped in a fantasy where he lives with his sister, Goldanna, and her children. This Goldanna is actually a demon attempting to trap Alistair in the Sloth Demon's domain. The Warden must convince Alistair this Goldanna is not real in order to escape the Fade. With certain dialogue choices Alistair can be convinced to battle alongside the Warden against the demons.