I know you aren't implying that a short rope is automatically crappy one, but it kind of sounds like it.
My advice: Give your friends the best you have.
Let them share the great safety gear you have, and the great safety techniques you'll show them.
What are your belay anchors? Trees and boulders are OK if you have plenty of sling material. And don't forget, when each person reaches your belay, they'll want to tie in to it somehow, to be safe up there.
With a rope, each will all need a sit-harness to tie into. No belay devices, but biners might be handy.
The first time I climbed a grade-4 "cliff", I was given good top-rope stuff to keep me safe. One of our ropes that day looked pretty tatty, although not damaged. None of us would volunteer to use it.
So do you friends a favor, and show how you take their safety seriously.