Can she cock a Shadow or a Quest? A Quest runs about $85, and the Shadow is (still) $125 at Walmarts that carry them. I don't know of any others in that power range that cock as easily.
The B20/B26 is actually harder to cock than the Shadow/Quest, and slightly less powerful, so that's probably out.
In a lower powered break-barrel, there's the 600fps (rated) Crosman 795 - should be an easy cocker, but it might be a little weak for what she wants. I've got no experience with this rifle. Probably in the same league - might be a little more powerful - is the Gamo Shadow 640. It advertises about 640fps, and is lighter and easier to cock than a Shadow 1000.
In CO2 there's the QB78 that another poster mentioned... but the Crosman 1077 is a repeater, and the Crosman 2260 is advertised as 600fps - in .22.