Famous five-esque movie or tv show episode

As a kid i watched something, pretty sure it’s a movie but am struggling to find anything on google with what i remember so might have been a tv show episode.

Probably 90s, maybe earlier, unlikely to be later than 2003

4 kids and a dog (not famous five) camped on an island

The dog was called prince

One of the girls was called something like lucy-anne or lucy-ann or lucianne

I think it was 2 boys and 2 girls but am not too sure

I thought with the name of the dog and possible name of one of the kids I’d be able to find it on google but i haven’t had any luck