Would a pistol or rifle be better for home self-defense?

Given the objective of intimidation & the wife's skills, STRONGLY suggest a 12 GA pump shotgun. VERY INTIMIDATING & very effective at close range if (God forbid) you actually have to use it. Pistol & rifle requires much more training.

If you want to encourage a home invader to turn around and leave, shotgun.
Those not willing to stand and shoot will run when they hear a shotgun rack.
And for a 3 meter firefight, you really only need the min legal length on that shotgun barrel.

Short of that, both pistol and shotgun greatly reduces the over-penetration threat of a round hitting someone inside another room in your house, or outside or in the next house after going through a wall or window.

Try a shotgun and who knows you might enjoy trap shooting.

I'd recommend a shotgun. It's a point and shoot weapon that requires minimal training. Mine's loaded with birdshot. This reduces the chance of penetrative a neighbor's house.

LCpl Mark Lefler If someone is breaking into your house, intimidation might not be enough against criminals that might mean harm to you and your family. Before you buy a weapon have a talk with your wife about the possibility of using that weapon to protect your lives. Both of you need to find out what gun/rifle/shotgun ranges are in your area and what their requirements are. Both of you need to know how to fire the weapon enough so that you are comfortable with it. You both need to know how to load it, and at least one of you needs to know how to clean it and have a safe place to store it. Having a weapon for home defense does no good if you do not feel comfortable with it.

I’d imagine you might get more votes for a shotgun over a pistol. I say go with what you’re most familiar and comfortable with. For me, that would be my pistol, which is a Beretta and I can load it with 15 round mags (hollow points). While big sounds and large blasts can certainly be scary and effective, I also want to make sure I have enough to stay in the fight if it comes to that. I am proficient with a shotgun but if I’m using a long gun, I’d prefer an AR-15 style weapon. Again familiarity.

If you're going to commit to a firearm as far as owning one goes, for that purpose, the will to use it should not be questioned. Two things make for effective and safe use of a firearm in any capacity of defense: proper training, and the will to use said firearm. The former can be acquired usually at the same place where the firearm is bought. I've yet to come across a gun shop where classes on proper usage and carry weren't advertised. The will to use it is something that requires an in-depth introspection. No user can afford to hesitate with said firearm once it's drawn and bearing on the assailant. Hesitation kills like complacency does.

That said...

The one you're more versed in will be the more suitable for home defense. If you're more suited to a rifle then go with that. If a handgun is something you have more practice with then go with that. A shotgun in 12 gauge is of little use if you don't know how to safely and effectively use it.

I'd go with a shotgun but have a pistol under within easy reach. If someone breaks into your home in the middle of the night and stumbles upon your bedroom you may not have time to get the rifle. My two cents worth.

It depends. I know that is not much help but please allow me to rattle on.
_Are you more familiar and comfortable a long arm (shotgun or rifle), handgun or less lethal [not the same as less than lethal] (air pistol with nylon rounds or pepper balls, taser etc.)?
_Are you and the any occupants really ready to kill an armed intruder?
_What is the layout of your home?
_What is the possibility of a high velocity round leaving your four walls with the power to injure bystanders?
_Are there children in the home? Are they old enough to understand the purpose and consequences of a firearm?

I live on a farm.
_My first line of defense (warning) are ducks and horses. When someone enters the property, they let us know immediately.
_My second line of defense consists of my livestock guardian dogs and geese. that combination has run off coyotes, bears and teenage boys intent on mischief.
_My third line of defense is some bad ass Basset Hounds [If you trip over them, they will lick your face and you may never recover]
_My fourth line of defense is me and a .50caliber air pistol revolver with a combo of pepper balls and less lethal nylon rounds.
_My fifth line of defense is a combination of me and the wife with a.45 pistol and my birding shotgun loaded with snake shot.

No one bent on mischief has ever made it past the Basset Hounds alive.

Some really great advice here.
I worked as a retail salesman in gun stores and finally got my FFL and opened my own shop. Whenever a customer asked your question, the very first question I asked was "Are you prepared to take a life?" Many answered no, they only wanted to intimidate. I then suggested Mace or pepper spray. Lost some sales that way, but I have to sleep at night.
If the customer was convinced a gun was necessary, I then suggested a firing range that rented firearms. Go and find out what you and you wife are comfortable with. Lost more sales.
Finally, with a customer that still wanted to purchase a weapon, I pointed that my weapon of choice in my house was a Winchester Defender 12Ga loaded with 6 rounds of double-ought buckshot. That will take down any man alive (also big bears). If your wife is not comfortable with that, get a 20Ga or even a .410.
Good luck and I believe you are showing some good common sense.