I doubt you'll find anybody with track experience on those tires. I could be wrong

 

Aufitt has done laps with IRC's I'm pretty sure.

 

A few selections from this Google Search

Motorcycle Industry Council
Tire Guide
All you need to know about street motorcycle tires
http://www.mic.org/downloads/mic_tire_guide_2012v1.pdf

Motorcycle Track Day Tire Pressures - What Should You Set Your Tire Pressures At For The Track? -TheRideAdvice.com

5-things-you-need-to-know-about-motorcycle-tire-pressure
https://rideapart.com/articles/5-things-you-need-to-know-about-motorcycle-tire-pressure

 

I know the stock tires are not the greatest, but she's not that fast.......

You wrote the main important thing, I think!
Not that fast, that may let others drive harder on the public roads with the IRC's.
In case, your wife is riding her bike with the recommened tire pressure all the time, leave it like that. Minimum in the beginning.
Don't change to many things in one time.
And keep in mind, the CBR250 is on pretty low recomened psi, already.
29/29psi (2.0 bar) single.
And 29/33psi (2.0/2.25 bar), with 2up
(Actually, in Thailand that are the numbers)

Out of my own experience, with only about 0.1 bar lower pressure on the IRC's, plus average normal (for me) driving, they got a bit slippery in quicker corners

 

Out of my own experience, with only about 0.1 bar lower pressure on the IRC's, plus average normal (for me) driving, they got a bit slippery in quicker corners

Shouldn't lower pressure normally increase grip as more rubber meets the tarmac.