Tea with Wendy Darling is away on a day at sea. I know it was in the afternoon if I recall correctly it was 3ish. It is held in Studio Sea Deck 4 Mid Ship.
Check in your daily Navigator in the morning on the Sea days. Passes have to be picked up for this event before hand. Usually offered around 9:30 am that day. The times for the tea will not be posted in the Navigator that is why it is important to get your passes ahead of time, first come first serve bases.