I agree that the phrase is dated slang, and it makes sense in this context because it's part of a joke: nobody is really talking about taking Gwenifer Arscott's virginity, which may or may not exist (I'm guessing not, but I haven't read the novel). So the speaker is using an expression that everyone would understand but would also find slightly comic. Nobody would use the phrase seriously these days. So if there's a Slovak slang term for taking someone's virginity that would have been more common in, say, the 1950s, that might be your equivalent. Barring that, I would go for a term that's humorous, a bit crude but not too crude.The whole phrase in the context:
‘I never,’ said Strike (it was a joke of long standing), ‘shagged Gwenifer Arscott.’
‘Well, have another bash, Diddy, you might strike gold this time. Time someone took her cherry. And speaking of girls neither of us ever shagged…’
Source: Robert Galbraith: The Silkworm
"take his/her cherry" is a common, somewhat crude expression. Note it may be a)figurative or b)extended.
a)The former would apply in a non sexual situation. Recruits lost their cherry in the first battle.
b)The latter would apply for sexual events that don't involve intercourse of male and female.