Where can Luna lay?

Our coop is configured so that the nesting boxes are at counter height. My sweet little Silkie, Luna, has no way to access that area since she doesn't fly. Will she know to pick out a spot on the ground? Is there something I can/should do to prepare a nesting spot for her?

She's five months old. I know Silkies aren't big layers, but she will lay a few eggs here and there, right?

 

Thanks so much for the advice and the compliments Luna is from MPC, we've been very pleased with how pretty and calm she is.

I just hope the other chickens don't decide to try to lay where we set up a nest for her - it's so easy to get the eggs from the nest up above on the counter.