Me and my daughter are traveling to Hong Kong from the United states for Cosmoprof next week.

You may buy Airport Express Travel Pass with one/ two single journeys for HKD 250/350. Apart from one/ two rides on Airport Express, you can use it to ride on MTR (except East Rail Line First Class, Lo Wu and Lok Ma Chau stations), Light Rail and MTR Bus (Northwest New Territories) for three consecutive days. Also, you can add it up and use it an normal Octopus cards. :)