No, no that was not my intent. Just an MEI telling you that skills take you to one level in a twin, and there are airports and scenarios where it literally doesn't matter your skill level, the twin adds more risk not less.
Until you buy up to a level where your twin has enough excess horsepower to climb on a single engine in the takeoff configuration with a draggy windmilling prop on the dead side, you have a built in risk zone where you're going to impact the ground in a few seconds. It's just physics.
I'm just saying this because you haven't sat down with an MEI yet and worked the numbers. Once you do, you'll have some interesting information to share with your wife coming from a place of knowledge instead of perception.
You can mitigate it some by load. For the safety level your wife is expecting, here would be a typical conversation leaving a hot, high, airport with a short runway:
"Two people only, two bags, and we only have enough fuel on board to fly to the big city airport over that direction that has a 10,000' runway."
It all depends on your mission. I love flying light twins. I don't kid myself on their capabilities though. You don't sound like you would either.
But you're paying for it dearly. Pushing 30 gallons per hour even in a light twin, and two engines and two props to buy when overhaul time comes. The price tag goes up on a steep curve when you want true single engine performance and speed.
Deep pockets and a smart brain and you'll get what she perceives you'll be getting. That's all I'm saying. Buy wisely. Fly wisely.
Her "need" for "safety" might go down a bit if you show her it'll cost at least $100,000 more in acquisition costs and maintenance over the ownership period, and more than double the operating cost.
Easiest way to show it? Grab the rental price list of a big club with light twins and point out that the ones on their line unless flown very light and in short hops, will not be as safe at certain airports, as the column of singles and let her compare prices.
If you're okay with the price tag, go for it. I love flying 'em as do a number of folks here. Technically I can also teach in them, but don't have access to one with the right insurance, etc yet.
But keep in mind you can be Bob Hoover and Sean Tucker combined and there's still flight modes you can put yourself in willingly in a light twin, where your only option is that you're going off the runway, through the airport fence at a high rate of speed.
The gear takes 13 seconds to fully transit, you've lost an engine and due to drag you only have four seconds left in the air, and you can't go up. That's the reality of light twins at takeoff under most flight conditions.
Just be aware that her perception does not match reality. Even a pilot's perception of twins and safety gets a severe "tweak" once they start training in one. Mine did.