What were these 90s TV shows?

This is driving me crazy...when I was younger (late 90's early 2000's) I used to watch a show set in Australia I think where the cast were children looking for a pearl shaped like a kind of four leaved clover...it focused on a group of children I think and I remember one of their brothers was a diver and there was a "bad" man also trying to get the pearl.

Also does anybody remember another show, also Australian I think, where a girl has come over from England to stay in Australia and is living in some kind of animal rescue centre where at first she doesn't get on with the owners son??? I remember one episode when she was upset because it was summer at christmas so they had a christmas party on the beach???

Sorry about lack of detail but is really driving me mad!