From "The Court of the Queen of Flowers."
"The best white rose among the hybrid teas is probably the Kaiserin Auguste Victoria, frequently known since the war as Edith Cavell. It is a beautiful cream white blossom, deliciously scented. Its only rival among the white roses is the Frau Karl Druschki, a hybrid perpetual, which has been similarly re-christened "Snow Queen," and which bears flowers of enormous size."

It's possible that rather than Edith Cavell having been bred by Chaplin Bros. in 1918, it could instead have been introduced in the U.K. by that firm in that year