Well, looks like two challenges here, shade and clay soil.

Some shade grasses include hakonechloa, carex, luzula, chasmanthium. Calamagrostis will tolerate shade. The taller grasses (5'+) are going to be sun lovers and not perform as well in the situation you described. You could try a Miscanthus maiden grass. They aren't going to do as well and may not bloom, but may get by. You might want to consider a clumping, screening bamboo or other type plant for that spot.

Of all plants out there, grasses can tolerate clay soil better than most. The important factor is drainage. Clay soil that doesn't drain well can be a real problem, especially in shade. You may need to amend the soil if it doesn't drain. You can mix in sand and organic materials into the clay. Be sure to plant the grasses slightly higher without burying the crown, especially if drainage is an issue.

Thanks for the suggestions. I will pass along your thoughts and see what she says.

Alexa