the lost Mikaelsen siblings

Niklaus has been keeping a locked coffin with him for a thousand years. It is his older sister, who Mikael and Esther cursed into the coffin. They put a sleeping spell on her, so that they could channel her magic and make her siblings vampires. When the Mystic Falls gang are convinced that there is a weapon in the coffin they wake up the older sister. She was the only one when the Mikaelsons were younger that kept them from fighting with each other. The Mikaelson siblings see her as their second mother. What happens when she wakes up and casts a spell to protect her siblings instead of kill them? What happens when she has news that affects all of the Mikaelsons?