Sexlessness is an attitude, not a litany, or lack of litany of sleazy conquests.
She ran a brothel in, you say cafe I say brothel, haven't you ever watched 'Allo, 'Allo?
Now she may not have had that much sex during the WWII simulation as she was the was the Madame, but Kathryn would have had all the correct memories implanted into her of being a young whore( correct word!), and the German soldiers would have been handing over money to her to sleep with Seven of Nine and the other waitresses working in her "bar".