While Lorna/Lana is on the phone in Frasier's bedroom, she speaks to her son. She shouts at him to put his brother on the phone but, when viewers meet her son Kirby later in the series, there is no mention or appearance of a sibling.
Frasier mentions two film versions of "Wuthering Heights" when Roz asks him. But depending on whether you count television films, there had been no less than six and upwards of a dozen at the time this episode aired.