While in Roatan we didn't swim with the dolphins but did go twice to dive with the sharks - Cara Cara. Face to Face. I'm not sure about now, this was 4 years ago with some really fun former lawyers/Italian national kayak polo players. Plus I like the connection lawyers to sharks. The 1st time was to watch a feeding. Everything in the area comes out for the show. Small Sargent majors and groupers at least 20 inches long swimming right in front of you, close enough to rub their bellies. There were about 10 grey reef sharks, buy the video. David and I went back and swam with the sharks and one DM a few days later, very cool. It was just the 3 of us. One had a fish hook in his mouth and Maurilo swam beside it tugging it free, no video.
In Belize we were lounging on one of the small cayes and watching our friends do a couple of exercises for their AOW when we noticed the dolphins playing with them. Unfortunately they had taken the boat just far enough away with my mask, fins and snorkel!
Now that we are in Curacao no, I have yet to encounter dolphins in the wild but I hear about others all the time. That's just luck; to swim with a manta, whale shark or dolphin. Of course visiting divers dive far more times (a day!) than I do.
Have her get her OW certification and you'll have more options.
Boston, Almost forgot to ask; what's the difference between an HBO doc and an HMO doc? You play one on TV?

SB names are fun like deciphering license plates while sitting in traffic.