TV star and former model Penny Lancaster resembled a shimmering mermaid on Tuesday night as she stepped out to attend the world premiere of Ocean With David Attenborough.

Penny was joined at the star-studded event by her model son, Alastair, whom she shares with her musician husband, Rod Stewart.

Looking glamorous and relaxed, the Loose Women star, 54, rocked a gooseberry-green maxi dress embroidered with a geometric pattern of sequins. She paired her frock with a fluffy chartreuse-hued coat, strappy bronze heels and a quilted clutch in gold.

A pair of amethyst drop earrings rounded off her red carpet look.

As for hair and makeup, Penny opted for a siren-inspired aesthetic complete with voluminous waves a la old Hollywood glamour. She added lashings of mascara, rosy blusher and a slick of glossy pink lipstick for extra va-va-voom.

Alastair, meanwhile, towered over his famous mother in a dapper tailored outfit comprising a flecked grey jacket, a crisp white shirt and a pair of dark trousers. The 19-year-old wore his chestnut mane in a low bun and accessorised with an edgy striped bow tie.

Penny and Rod's eldest son is a budding model with a place at the Jimmy Choo London Fashion Academy. During an appearance on Loose Women, Rod's wife said: "Alastair is waiting for his A-Level results but he's been given an offer from the Jimmy Choo London Fashion Academy in London, doing a three-year degree in Fashion Design, Entrepreneurship and Branding. So I'm very proud of him."

Beyond this, he's also starred in a fashion campaign for clothing brand, Palm Angels, appearing on a massive billboard.

Aside from Alastair, Penny and Rod are also proud parents to a son called Aiden, whom they welcomed in February 2011. The 'Maggie May' hitmaker also shares daughters Sarah, Renee, Ruby, and Kimberly and sons Sean, and Liam with previous partners.

Penny and Rod, who tied the knot in 2007, have been open about their blended family dynamics. Reflecting on his blended family, Rod previously told PEOPLE: "I have to be several different fathers because of the different age groups of my kids.

Penny, meanwhile, told HELLO! in 2017: "It's been a learning curve but a wonderful one. It's so lovely that we're all so close and they all turn to me for advice, to talk about dad, boyfriends and career choices. It's a big happy family now."