I suggest not going to Eden Beach either - not a great dive and not a great beach - it's terraced and in one area there's a low retaining wall you step over to get to the water. Wannadive is a good crew though and their boats are there.
Dive Friends Yellow Sub is the nearest cruise dive operation being just north of the pier. There's an average shore dive there plus they keep boats there.
Kralendijk might have enough for your wife to do - there's some shops around the pier. I can't imagine there's many cruise excursions and I can't think of where they would go that's worth it. It's a real small town.
Check with the Plaza Resort on Bonaire to see if they have a day pass option. One of the better beaches, large pool area, Coconut Crash is a fun beach bar. Toucan Diving on-site for you at the south end of the resort plus just north of the beach is the 18 Palms dive site. A couple times with Toucan we did one or two tanks in the morning - they're not afraid to burn the gas to get to great sites like Rappel plus they post single tank afternoon dives on a signup board - it's how we did Forest. Us, a dutch couple and the DM who led us down then turned us loose for an hour. You'd be back by 3ish and the Plaza is on the south end of Kralendijk
Another option would be shore diving at Bari Reef with Dive Friends at Den Laman. They also keep boats there and it's almost directly across from Klein - IMO Forest is the go to boat dive there.Coco Beach Club is directly to the south of Den Laman - arguably one of the better beaches there. There's likely a cruise excursion there.
The only issue arriving at 8am is you might miss the morning boat. Find someone doing single tank dives and catch the 2nd dive plus the 1PM ish dive. From Bari going north is Sand Dollar condos, past them Buddy Dive then Habitat. At either it should be easy to find a buddy if you need/want one. From Habitat's dive dock a short swim north puts you on Cliff - one of few vertical walls off Bonaire. The LaMachaca wreck is out there also as you drift back to Habitat but don;t make it a destination, it's not a great wreck.
I've also read of people using VIP Diving. I believe but do not know that it's escorted shore diving and they provide the ride.
On Curacao you dock at the pier just north of town, walk off and are at Rif Fort/Renaissance Mall. The Renaissance hotel has a Reno sized casino and south of there is the harbor, swinging bridge and old downtown on the south side - all the brightly colored old buildings/shops you see in photos. A small museum, some historical buildings, a farmers market on the south side of the harbor. Much more to do on a non-dive day.
