And what is the point of FF mirrorless? It's compact and lightweight?
Just because mirrorless starts in the p&s region doesn't mean it's only good for holiday snaps!
The main advantage of mirrorless next to the missing mirror (= smaller design) is that the sensor can see the picture all the time, so you can have lots of information previously missing in the evf - like focus peaking, zebras or numerous other electronic hints.
With a good sensor (ff), a good electonic viewfinder and the appropriate software pro mirrorless will make the current dslr designs look like they are from the stone age, "with mirror" will become a nice market in 10 years from now. Why do you think Canon invested so heavily in their dual pixel sensor tech?
She shoots jpeg and until she has problems Raw can wait.
As you probably know, next to adjustable wb esp. with Canon raw has much more dynamic range (less danger of clipped whites, cleaner shadows) - and you can always just convert raw to jpeg or lossy-dng afterwards to save disk space, but not the other way around :-)
I'm impressed at looking at the quality of the pics she has taken with the 70D so far and if I get in a situation
where my 7D struggles I'll get her to take the pic that I want.
It's great you're happy with the 70d, but you might want to look again - judging from any the studio samples the new sensor isn't much of an advancement over the 7d, maybe - and that's stretching it - 0.5 stops @medium iso.