As she visited, the gallery confirmed the duchess — formerly Kate Middleton — will pose for a portrait in the near future, though no decision has been made on which artist will be commissioned.
Tilley said she wasn't worried the duchess would be put off the Freud exhibition by all the flesh on display — a roomful of it Tilley's.
"I'm not embarrassed about her seeing me naked — I'm a human being," Tilley said. "I may not be the most gorgeous one under the sun but that's what I am."
"It's art, you know. Poor woman, I'm sure she's seen things before," she said.
National Portrait Gallery: http://www.npg.org.uk/
Jill Lawless can be reached at: http://twitter.com/JillLawless