Hi @tigerswing2,
Thank you for your question.
I think decorative stones would be a great idea, but you'd need to extend that edging so that the soil doesn't collapse.
You could use edging pine and timber stakes to continue the barrier.
Once set up, you might like to lay down some weed mat to prevent weed growth, then cover it with decorative stones.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob