Mirna Dendrar originated from Thundertree. Her family ran a herb and alchemy shop. She was forced to flee as a young girl after undead overran the place. She married Thel Dendrar and they had two children, a boy called Nars and a daughter, Nilsa.
They moved to Phandalin but when the Redbrands took over the town her husband was murdered and his body fed to a nothic living in the cavern beneath Tresendar Manor. Mirna and her children were enslaved by the Redbrands and kept in pens, waiting to be sold. However, they were freed by The Harlequins