Fiji : Beaches in taveuni and islands off Viti Levu - Naigani, Toberua

Hi there
We're going to Fiji, not our first trip. already been to Yasawas, Kadavu and Wananavu (north Viti Levu)
Presently I am a diver, my wife and my daughter 16 yo. do not dive, just chill out on the beach or at the poolside.
I don't want to selfishly leave them on a muddy beach or nothing to do while I am getting a blast below water, so I need both good diving and ok beaches or even more.

I said good diving, so no Mamanucas nor Yasawas, please. Besides that, we've already been to Nacula. You can't do better than Oarsman's Bay.

We are planning to go to Taveuni 4 days and some other outer island for 4 or 5 days. My wallet is not super extensible too, I would shell out 300/400usd max a day though since it's not a longer stay. No Qameas nor Namenas for me, unfortunately...

Taveuni, I know it is not a beach place but an awesome good diving place. i saw Coconut Grove, anyone been there? would you recommend for th ebeach, location? otherwise where else in Taveuni?

otherwise Naigani seems a very good compromise but I haven't heard almost anything about the place. any reports or opinions? Toberua seems very nice too, any feedback?

thanks in advance for all your ideas.
Luko