Hi Elizabeth. Hope you find someone - I've looked several times for organisations/individuals in Fiji but haven't come up with much. I think even their IYA 2009 contact was media-related. They have some wonderful skies outside the urban areas but like all tropical areas the viewing is pretty much seasonal.
I did come across a reference to an Associate Professor of Physics at the USP, Suva, who had written several articles on amateur astronomy, Anirudh Singh. There are no tertiary astronomy courses in Fiji so his interest is probably in an amateur vein. There is a contact for him at the USP website.
As a tourist to Fiji a few times, I kept my eyes and ears out for a sniff of astronomy but didn't find anything. Mind you, as a tourist you're only flitting around the periphery of Fijian society! If there are any groups they're probably in the middle class or ex-pat sections of the larger cities like Suva, life in most rural areas being pretty much subsistence.
I've had some great astronomy experiences in Fiji with nothing more than a battered pair of binoculars. As opposed to the family you are trying to help, I was getting northern sights not viewable from home! I was there in 2009 and saw the partial solar eclipse (China TSE). It was a fantastic day - staff and guests at the small resort wandering through and enjoying the views through a generous piece of Baader filter mounted in a sheet of cardboard.
Good luck, you never know what might turn up in response to your query.
Cheers -
