Let my sister borrow my Jeep for a long drive over the last weekend, drove it to work and its spewing coolant out of what I think is the radiator.

Has anyone had a similar leak to this?

Also is it possible to drive it 20ish K's to my house

 

No, do not drjve it. That is major coolant loss. do not run motor. Now if motor has completely cooled to ambient, ran fine before shut off, you confirm it has oil, sure you may start it momentarily say if the jeep need be moved some tens of feet for getting it towed. just run it for seconds from dead cold. But no, she is dead to driving til fixed.
You may simply have a torn lower hose, easy fix. I assume she she stopped driving before over heat damage occured? I hope so. I lost that much, lower hose went, huge steam gusher out the front, stopped engine immediately, no additional harm! I was offroading, in the desert. stuck a bucket under the leak, caught most the fluid, we was able to cut off torn end of hose and reuse, replaced with new upon return home. tear occured right at the hose clamp, so all we done was trim maybe an inch off the length to cut out the tear, hose was long enough. We had enough spares in our happy band of campers now as we are a xj group. bunch of wacky xj campers!