What is the theme in The Flame Trees of Thika: Memories of an African Childhood by Elspeth Huxley?

Loyalty is a theme seen mainly in Elspeth's family and most commonly in Tilly's loyalty to Robin. Tilly has had a difficult life as Robin's wife. The family was once wealthy enough that Elspeth had a nanny and Elspeth recounts the story of having overheard the nanny say that Robin "had a hole in his pocket."