I tend to think the .410 would be more effective than most give it credit for. For instance, I have killed 2 deer with one shot each, 140 and 165lbs dressed, with a .410 at around 50 yards both times. And most typical self defense situations are far closer than that. A 90gr slug at 1700fps and 700lb/ft of energy is going to ruin your day, and I can't imagine that 4 pieces of 000 buck are going to feel much better. Even a load of #4 birdshot is going to be a very stiff deterrent. A load of #4 shot to the face from 10 feet is going to stop you dead in your tracks, and probably remove your eyes in the process. While I would only use 3" shells, I can't see .410 being any less effective than a .380, and probably close to or better than a 9mm.
And as far as the Judge is concerned, who says you must carry shot shells? It also uses .45 Colt, which is a damn good defense caliber IMHO. The 45 colt has similar ballistics to the .45 ACP, and many consider that to be acceptable for defense. While it's not the best by any stretch, I'm quite sure that it would be as effective if not more so than many of the "pocket guns" that are being carried by many. I know I would feel a hell of a lot safer with 5 rounds of 45 colt/.410 than I would with 7 rounds of .32acp or .380. About the only compact option (I am not stating the judge to be overly compact) I would think to be far and away better is a .357 mag, and the recoil from a light snubbie is very stout, probably more so than most women would care for.
While it may not be the best option ever, I don't see the Judge as being terrible by any means. As long as the proper load is used, I see no reason why it wouldn't be as effective as most other defense pistols. And it also has a bit more versatility and a huge cool factor.
Some may feel differently, but I wouldn't hesitate to carry a Judge. With 5-225gr .45 colt rounds packing 500lb/ft of energy at 900 FPS, I would feel very safe indeed. Maybe add a round of 000-buck or #4 or BB, and I would be good to go.
It's only my opinion. You don't need to ream me out about it, as I know others feel differently.