This is one of those cases where there are two hostas with the same name. One is registered and, therefore, the "official" version of H. 'Blue Lady' while the other is a non-registered plant and needs to be renamed to avoid further confusion.

This cultivar is a Eunice V. Fisher plant that was registered for her by Peter Ruh of Ohio in 1998. It forms a medium size mound about 13 inches high with pale purple flowers that bloom in dense clusters in mid-July.

According to The Hostapedia by Mark Zilis (2009), "...close resemblance to 'Blue Cadet' and other H. nakaiana-types."

Hosta Helper will call this plant 'Blue Lady' (Fisher)
 

According to The Hostapedia by Mark Zilis (2009), "...The name 'Blue Lady' has also been used for a large, H. 'Elegans'-type plant."

Hosta Helper will call this plant 'Blue Lady' (Hostapedia)