Different spellings, Lishka. Knollmasculine for ladies to lounge on, Nell definitely female, for the males to perform on whatever activities they are encouraged to perform.
After all, as this is to be an Equal Opportunities pantomime the males must also have the opportunity to be lounged on, although I think we must leave it to the discretion of the cast to ensure that only ladies lounge on Knolls and only gentlemen on Nells.
Mind you, from what oZzY says, several Nells might well catch fire if he`s careless with his cigarette-ends.