Ruger made a compact .243 in the American. I have a .223 and a 7mm08 in the compact. It has a 12.5" length of pull. I would bet with a bit of looking you can find one. Our local Fleet and Farm has one on the shelf.
kwg
Wife has the compact model in 7-08. After her first session at the range, she smiled at me and said, "This is MY rifle!"
These are super handy but louder than hell... I'm sure you've got her set up with ear pro... but if not, arguably as important as the rifle.
If you are a handloader, this isn't an issue...
I load plenty of 243s for Boy Scouts over the years... depending on their ages ( I get them from 12 to 18 yrs old ).
25 to 30 grains of IMR 4198 or RL 7. I get the same velocities I am seeing out of my 6 x 45 ( my new toy ). They will drop any deer that ever walked...
Heck even with Blue Dot, 22 grains with a 100 grain bullet will run at 2500 to 2600 fps out of the muzzle, depending upon barrel length... and if you are shooting short barrels ( say 18 inches) Blue Dot will burn all that powder up in LESS than the 18 inches of the barrel... so it will cut down recoil, and an Muzzle Blast.
works in a 260 or 7/08 also...
Think of it as you are getting the recoil of a 30/30, but flatter shooting and more velocity.