dasmi,
Even a single shot .410 is not to be sneezed at, especially in the hands of a confident and capable shooter. Granted it is not an optimal defensive tool but it will definitely do the job, if the shooter does their part. And confidence in the gun is important to the shooter, do not denigrate either a single shot or a small bore. As unfortunate evidence of the effectiveness of that gun/caliber, there was a tragic case of double murder in a nearby city recently, and the killer used a single shot .410.
In this caliber (.410 is a caliber, not a gauge) I would stick to slugs or larger buckshot for HD. At close range it won't matter that much which is used but either of these loads will penetrate better than light loads of birdshot. Any less expensive birdshot load can be used for training, of course, but the heavier loads should be deployed for HD.
Do you know the old single shot shooter's trick of keeping a spare shell or two between the fingers? It makes reloading faster but has to be practiced, like all other shooting skills. It works very well with small diameter .410 shells, too.
I would recommend a butt cuff on this gun, it helps to have a supply of ammo attached to the weapon. Make sure the stock fits properly, it is hard for a petite person to shoot a shotgun with a too- long stock well.
Other than that, training and practice are in order. Teach her to use a barricaded position of her own choosing/preparation somewhere in the home, using substantial furniture to provide both cover and concealment as well as a barrier to physical attack. I usually suggest the opposite side of the bed from the bedroom door, back protected by the wall, cell phone handy to dial 911 (even a cell phone with no paid service can dial 911, a cell phone is a must-have because the landline might be cut), shotgun rested across the bed and aimed at the door, with a night light etc. backlighting the area behind the door.
Start off with 'normal' range practice and familiarization firing at 7 yards or so. Be sure you are familiar with and prepared to teach fundamentals of safety, basic gun use (example- if she cocks it and doesn't fire, then what?), stance, mount etc, even a .410 can hurt if not properly handled. With fundamentals down solid, practice on silhouette targets from the range equivalent of her barricaded position helps a lot in this drill IMO, if it ever gets real that is what she will essentially be looking at. Remember to check the longest distance in her home she might have to shoot, and keep practice ranges realistic based on that distance. Emphasize safety throughout, be sure to demonstrate that it is easy to miss with a shotgun at close range, and reinforce her willingness to shoot a target that appears in the door after "night noises" are duly challenged/warned. Teach her to reload instinctively immediately after firing and be prepared ASAP to fire again if necessary, there might be more than one intruder (or the first round might not stop the attack and a followup shot might be required).
If she is a starting-from-scratch new shooter this will take time, and multiple range sessions. Make range sessions as pleasant as possible, keep things as upbeat as possible, keep it short enough that she does not tire. Often women are actually better defensive shooting trainers for other women than most any man, believe it or not, enlist female help if you can.
lpl/nc (my wife didn't make me type that last sentence)
