Assisi...Basilica of St. Clare

I was in Assisi a couple of weeks ago. While visiting the Basilica of St. Clare I was struck by a stained glass window in the Oratory of the Crucifix. The window depicts someone, surely St. Clare, washing the feet of St. Francis. None of the volunteers could tell me anything about the window. Is there anyone on this forum who can tell me anything about the window? I've searched books, Google, etc. with no luck.