That place is the richest of Paris, my friends say is where counts and dukes live (
). There are LOTS of lovely incredible places to walk on in Paris - my favourite is between Chatelet and the Senne, near the Conciergerie. .
IT's not as crowded as the Latin Quartier and much less mercantile compared to Saint Michel, near Notre Damme. Actually, walking along the river is one of the best advice I can ever give you, from the Eiffel tower down near Notre Damme
There are, indeed, some lovely churches with stained glass and wild arabesques, but more important that seeng them all is to just be in the right mood as to enjoy them.
I think she must see the museum - it's a "must", especially given her keen interest on Egyptology.