It is not only for Lammaites. The web cited that registration in between Mar 15-21 for outsiders,
"Easter Egg Hunt: Easter Sun, Apr 4, 2pm: Tai Wan To/ Power Station Beach: 2-12-year olds, reservation absolutely required before Mar 14 for Lammaites, Mar 15-21 for others: Lamma Church of Christ in China, 45 Po Wah Yuen, Tel: 2982 0316, 2982 1459; 1 Back Street, Tel: 2982 1459. Photo galleries of last year's egg hunt."