A concrete stone (round, square or rectangular) could be made at a low cost with kids inscribing on it or perhaps someone stamping something nice in it, using those refrigerator magnet letters and then pulling them out. Also, leaves could be pressed into the concrete, vein side down, for a pretty effect.

That sounds very nice.

I spoke to the girl's best friend today, and asked her if she'd like to help and to think of an inscription. I think the idea of personal "stamps" will appeal to her.

Where do I get this, do you know?

I did see garden markers in a catalog I think it was jackson and perkins. Have you looked at any of the local garden centers? I think I saw one today at a wild bird and pet store today called back to nature it's in Media Pa. I bet there's probably a similar type store near you. Sarah

Elly,
The kits sold for this kind of thing run around $75. For less money, you can find the kids refrigerator magnet letters in grocery store aisles where toys are sold or Wmart or Target usually for a few dollars or perhaps the kids could inscribe using something else. I made a square stepping stone using Quikrete, a pizza box and pampas grass fronds set in concrete (which I later pulled out)and a round stepping stone with a castor bean leaf, vein side down, using a large deep dish pizza pan, for very little cost. Perhaps an art teacher at the school has some experience in this. If not, it's a fairly easy project. If I can find a link to one someone on GW made, I'll post it here for you.
Robin

Here's info on making basic stepping stones which could be applied to what you'd like to do.

Here is a link that might be useful: Stepping stones

Thanks very much.