Lydia Hawksworth is a rivial of Hyacinth. She appears in Series 5 in the episode 'The Rolls Royce'. The episode commences with Hyacinth leaving a community hall furious as she had only received 2nd place in a table floral decoration competition, whilst Lydia Hawksworth won first. It is revealed that Hyacinth dislikes Lydia due to the fact that at one of her 'Candlelight Suppers' she made a loud comment that 'Kiwi fruit is so lower middle class". Whilst on their way home she overtakes the Buckets in her new and expensive car. This prompts Hyacinth to drag Richard to an exclusive garage and 'borrow' a Rolls Royce (driving away in it whilst the salesman who had agreed to a test drive was stuck on a phone call). They drive to an exclusive looking country hotel, where Hyacinth know Lydia Hawksworth regularly takes coffee. Hyacinth's plans to impress Lydia with the car come crashing around her when the police show up and arrest her and Richard for 'stealing' the car. As she is being led away by the police Lydia pulls beside her in her new car looking both shocked and amused.
The Rolls Royce is her only appearance; she is not mentioned again.
Lydia has the same surname as Emmet. Although it is not stated, it may be that she is Emmet's ex-wife. The fact that she is able to afford an expensive new car and take refreshments at exclusive venues whilst Emmet is forced to live with Elizabeth suggests that she is exploiting his maintenance payments.
The actress who plays Lydia is not mentioned in the credits. That said, she only appears briefly on camera.