Per Rachel on her Instagram, the youngest daughter, wasn't there because she didn't have a passport. Apparently, she/they were not told that it would be a "whole family" visit until after Tyson left. By then, it was too late to get the passport for Marlowe because Tyson had left for Fiji already, and Rachel and Tyson both had to sign the passport application. Also, Marlowe was just 10 months old, and Rachel wasn't sure how traveling with a 10 month old and a 3 year old would go.