A third saint whose feast falls to day is St Elisabeth of Hungary, 1207-31. She is one of aseries of saints produced by the Arpad dynasty in Hungary. There is an online biography of her here, which has links to other relevant sites, including her shrine church at Marburg. With St Louis she is the co-patron of the Franciscan Third Order.
SS Elisabeth, Margaret and Henry of Hungary
Simone Martini 1318
Lower Basilica of St Francis, Assisi
St Clare and St Elisabeth, two Franciscan female saints
St Elisabeth of Hungary with Isabel of Portugal, wife of Duke Philip the Good of Burgundy
Petrus Christus, 1457-60
Groeninge Museum Bruges
This is the left wing of a triptych. The original triptych with the Mater Dolorosa in the central panel and St Catherine in the right wing was part of the collection of Margaret of Austria. The small triptych was probably commissioned by Isabel of Portugal who ordered the triptych at the time of her retirement to a Franciscan convent in Nieppe, France, in 1457. It later entered Margaret of Austria's collection. The panel shows Isabel of Portugal with Saint Elizabeth and features the typical, finely chiseled and almost doll-like style of Petrus Christus. (Acknowledgements to the Web Gallery of Art)
Isabel and Elisabeth are, of course, the same name, hence the association as well as the shared interest in Franciscan spirituality and the fact of both being of royal birth.
Here are two phpotographs by Genevra Kornbluth of the shrine of St Elisabeth at Marburg:
The Shrine at Marburg
Detail of the shrine base
There is a German language site about the church at Marburg here with expandable views of the church and its furnishings. There is another German site about St Elisabeth here, with reproductions of medieval paintings of her and also a picture of her copper gilt chasse of 1235-50