Thandiwe Forrester was the youngest daughter of Leabie Forrester. In actuality, she was a clone of Roz Forrester that was created shortly after the Adjudicator started travelling with the Seventh Doctor and disappeared from Earth. (PROSE: Original Sin, So Vile a Sin)
After the collapse of the Earth Empire, Thandiwe lived in the Empress' Summer Palace with her mother and sister. Gugwani died after venturing out of the palace, leaving Thandiwe and her mother to mourn. Tranlis Difarallio, a scholar researching the Forrester family, arrived to chronicle the lives of Leabie and her sister, and stayed with them for a time to write his book. Tranlis refused to eat the Cimliss' food handouts, and after a vivid dream where Roz Forrester slapped the food out of her hand, Thandiwe decided to do the same.
Once Tranlis had finished his book, he offered to take Thandiwe with him on his ship. Leabie was adamant not to let her leave at first, but after witnessing the Cimliss handouts transform those who ate it into Cimliss themselves, Leabie let her go. Soon after Tranlis revealed that he didn't just want to write the history of the Forrester's, he wanted to end their line altogether. Thandiwe was quick to defend herself when he attacked, and killed Tranlis with his own club. Then she set off in Tranlis' ship, hoping to rebuild the Earth Empire. (PROSE: Dependence Day)