Sonia Vorbarra Vorpatril was a Princess of Barrayar. Her father was Xav Vorbarra, her mother was a Betan woman from the Bureau for Interstellar Trade; she had a sister named Olivia Vorbarra Vorkosigan. She married a Vorpatril who was not in a Countship line and became the mother of Padma Xav Vorpatril.
Sonia Vorpatril was killed in Yuri's Massacre.
- Captain Vorpatril's Alliance chapter 7
- See author discussion at http://lists.herald.co.uk/pipermail/lois-bujold/2010-September/055474.html