These are wonderful little boats, there is also a Joel White version called the Haven.
The Doughdish, the H 12-1/2 and the Bulls Eye are all the same hull. The bulls eye has a cuddy cabin and more deck up front for rougher waters. I think the Doughdish is a "high end" model. Older Bulls Eyes can be had pretty cheap, and there are a lot of them in New England.
The glass 12-1/2's and Bulls Eyes are built by Cape Cod shipbuilding, the Doughdish is built by Edey and Duff. Still, the sail area, hull shape, ballast, etc., are all the same. The Haven is a centerboard version, in case 2' 6" draft is too much
If she wants to spend big bucks, go new, go doughdish. The Bulls Eye has active racing fleets up the New England coast, I think any 12 1/2 is probably welcome. There are still a lot of the old wooden ones sailing.
For a first boat, the Bullseyes are tough as a cob and cheap, I think with aluminum spars. The H 12 1/2 and the Doughdish have wooden spars and a more classic look. All are terrific little boats.