She wrote on Instagram: “So it’s the royal wedding, my sister’s 40th and my mum’s 70th birthday party at the Willoughby residence today!!!!
“I blame you @ladywilloughby for the dress code!!!! #whynot #happiness.”
Willoughby also posed next to a picture of Meghan and added: “She is soooooo beautiful. Just a wedding day of dreams. Congratulations to Meghan and Harry xxxx
Willoughby, who wed Dan Baldwin in 2007, previously spoke about the family plans to get out their wedding gowns.
“I dug it out – I took it into This Morning to the big steamer… It is filthy! I haven’t had it dry-cleaned. It’s a bit ripped. I will look a bit like Miss Havisham,” she joked.
Holly Willoughby dons her wedding gown to watch the royal nuptials