Tara is the daughter of Charles Palmer-Tomkinson, a longtime friend of Prince Charles. In 1988, Tara's mother, Patti, was skiing with the prince at Klosters when they were caught in an avalanche. She was injured but survived while another friend was killed.
While I would normally say that the family should have a reasonable expectation of privacy, I remembered that Prince Philip's mother was an excellent lip-reader! She reportedly could read lips in a couple different languages and could pick up on conversations from across the room just by watching the speakers.